Crankypants
Odds are that you know one. If you're a business owner, and you've been active on social media for a year or more, you've probably encountered quite a few. These are the people whom I refer to professionally as "crankypants."
Some industries are more susceptible than others, like restaurants and retail. I had one incident where a customer complained about her lack of vegan options on the menu for a restaurant client's "Meat Lovers Extravaganza." You can't predict when the crankypants will show up - you have to know ahead of time how you will respond to some standard scenarios:
1) If the complaint is founded in reality - meaning the customer received poor service or had a bug in their meal or something clearly unacceptable - you simply grovel. You do whatever it takes to make this right. Give your social media manager some tools for their toolkit, like a free meal coupon that he or she can offer to your unhappy customer at any hour of the day or night. Social media is a 24/7 job, so unless you want YOUR phone to ring at 2am on a Sunday, equip your social media manager ahead of time with some pre-approved giveaways.
2) If the complaint is a matter of perspective - ie: the meal "wasn't good" - you may still offer a free meal, but personally I think that if the complaint is subjective, you are not obligated to do so. Not everyone is going to love every dish that you prepare, and as someone who likes to eat out, I may be disappointed if I don't LIKE something, but I don't expect my money back. This will have to be your call but again - something to discuss with whomever manages your social media before they began working. Don't wait until an issue arises to develop a crisis management plan.
3) If the complaint is out of left field - the vegan complaining about our Meat Lovers Extravaganza comes to mind - you might simply ignore the message. What????? Yes, I just said that. You are the boss, and I will always do what you tell me to do. But I believe that some crankypants do actually complain as a hobby, and that they are actively searching for people who will engage in battle just for kicks. I've found that folks who've left my client an "out of left field" negative review have OFTEN left a LOT of such reviews, which says more about THEM than it does about my client.
When you run across these people, your best bet may simply be to not engage. I will hide the comment if that is an option, but I never DELETE comments. If it's a private message, just do not respond. If they message again, perhaps have legal boilerplate that you use for your reply. Something super generic and non-confrontational. Have a strategy that you've discussed with your social media manager ahead of time for dealing with folks who appear to be complaint hobbyists.
The bottom line? Crankypants can actually represent an excellent customer care opportunity. Try to turn that frown upside-down! Have a plan, communicate it to your social media manager, and be consistent.
Call me if you need help!