Delta Air Lines rescheduled my flight by 9 1/2 hours. Do I have to accept this ticket?

Dianne Ness and her husband were stunned when Delta Air Lines rescheduled their upcoming flight from Boston to Phoenix by 9 ? hours.?

They were looking forward to landing in Phoenix, picking up a rental car, and making the scenic drive to the Grand Canyon while it was still light outside.

"The new flight would have had us driving through the Grand Canyon at 1 a.m. -- an ill-advised idea, especially for someone who does not know the area," she says.

But they were even more surprised that Delta only offered them one option.

"You can cancel the flight," a representative told them. "But you purchased a nonrefundable flight so all we can do is give you a credit for future travel."

True, the Nesses had Basic Economy tickets, the most restricted airfare Delta offers. But did they have to accept Delta's offer?

Ness' mess begs several questions:

• What are your rights when an airline delays your flight?
• How do you turn an airline ticket credit into a refund?
• When will airlines stop lying to us?

But before we get the answers, let's take a closer look at Ness's Arizona vacation.

"It was the only option"

Faced with either losing the value of her flight or accepting the ticket credit, Ness did what she thought she had to: She canceled her flight.

"It was the only option I was given," she says. "I took a credit for future travel, which was nontransferable and had to be used by the end of the year." (Related: Should this Delta Air Lines flight change lead to a refund ?)

This is typical for airlines. They give you the informationthat suits their business interests. Yes, it's true that Ness and her husband qualified for a ticket credit. But there was more to the story.

Lawmakers are on to such tactics. The U.S. Senate version of the FAA Reauthorization bill would have required airlines to disclose all passenger rights -- not just the ones that enrich the airlines.

Ness thought she was stuck with a ticket credit that she'd have to use by the end of the year but might not be able to. And if that happened, Delta would be able to keep all of her money without flying her anywhere.

What are your rights when Delta Air Lines reschedules your flight?

If your airline delays your domestic flight, you have rights under federal regulations.

If an airline cancels your flight, it must offer a full refund or a new flight of the airline’s choosing?

The airline may also owe you some compensation, depending on where you’re flying or the reason for the delay. By the way, that’s also true if the airline ends service to a destination. It has to offer a refund or a replacement flight.

If an airline delays your flight, your airline owes you less

There’s no requirement that your airline keep its timetable in the United States. For longer delays, though, federal law requires that the airline offer a full refund. It must be a "significant" delay, which airlines define differently. (If your flight is to or from a destination in Europe, you may be eligible for more compensation .)

You can find out more about your rights during a delay or cancellation in my complete guide on the subject.

But for Ness, the important question was: What is a "significant" delay for Delta?

The answer: 120 minutes.

"If you have experienced a flight cancellation or significant delay of greater than 120 minutes and no longer want to travel on your remaining itinerary, you can cancel your itinerary," Delta says on its site .

Delta also has it written into its contract of carriage , the legal agreement between the passenger and airline.

RULE 19: FLIGHT DELAYS/CANCELLATIONS

A. Delta’s Liability in the Event of Schedule Changes, Delays and Flight Cancellations

If there is a flight cancellation, diversion, delay of greater than 120 minutes, or that will cause a passenger to miss connections, Delta will (at passenger’s request) cancel the remaining ticket and refund the unused portion of the ticket and unused ancillary fees in the original form of payment.

And it doesn't matter what kind of ticket you have.

That small detail was missing from Delta's correspondence with Ness. In other words, it had told a half-truth and convinced her to accept a ticket credit.

How she fought back after Delta Airlines rescheduled her flight

Ness subscribes to Elliott Confidential , the newsletter where I disclose the travel industry's secrets. She started reading some of my back issues, where I covered passengers'? rights to a refund. And that's when it dawned on her that Delta had been less than forthcoming with her.

"My next call was to Delta," she said.

She asked a representative to pull up her reservation, which showed that Delta had rescheduled her by 9 ? hours. It would have her driving the back roads of Arizona after midnight, which she didn't want to do. (Related: Delta threatened to call police and remove me from a flight. Am I owed anything ?)

She also explained to the representative how disappointing this was to her and her husband. They had scheduled the Grand Canyon trip during the pandemic but had to cancel it. Now they had to cancel again.

And now Delta offered her only one option: She had to accept ticket credits that would expire soon.

The representative agreed with her as he reviewed her reservation. Everything had been done correctly.

And then she pulled out her ace.?

"I took a look at your contract of carriage," she said. (Related: Denied boarding by Delta Air Lines twice — can you help me get a refund ?)

That changed the entire conversation.

"The minute I mentioned the words 'contract of carriage' the representative interrupted me and asked if I was calling for my refund," she recalls.

Why yes, she said,? "I am."

And that was it. Mission accomplished.

"That was worth the subscription price," she said.

It's not just Delta Air Lines rescheduling flights. When will this lying end?

You can't trust an airline to tell you what your rights are. That's why I had to create this site and the email newsletter to which Ness and tens of thousands of others subscribe.?

It's why the Senate is requiring airlines to disclose passenger rights online and in their tickets, which is long overdue.?

When I hear from readers like Ness, I wonder how many other people have simply accepted an airline's half-truth and taken an expiring flight credit, even though they might never use it. Is it thousands? Tens of thousands? More??

I also wonder how much money the airlines have made by telling their passengers a half-truth.

Ness learned the truth and pushed back. You can, too. We publish the names, numbers and email addresses of all the airline executives on this site . A brief, polite but firm email citing your rights should help you get what you deserve the next time an airline reschedules you.

And if it doesn't? Well, you know where to find me.

Christopher Elliott is the founder of Elliott Advocacy , a 501(c)(3) nonprofit organization that empowers consumers to solve their problems and helps those who can't. He's the author of numerous books on consumer advocacy and writes three nationally syndicated columns. He also publishes the Elliott Report , a news site for consumers, and Elliott Confidential , a critically acclaimed newsletter about customer service. If you have a consumer problem you can't solve, contact him directly through his advocacy website . You can also follow him on Twitter , Facebook , and LinkedIn , or sign up for his daily newsletter . He is based in Santiago, Chile.