Your dirty laundry doesn’t belong anywhere near your social media pages. Customer service is a function of face to face interaction, phone calls and emails. Never on Twitter, Facebook or anywhere else that a couple of billion people can see it.
If you use it that way, STOP. Begin by monitoring your social media pages, hire someone if you need to. Monitor and respond immediately with a counter response. Customer service departments are really PC for complaint departments. There are abundant complaint sights, you don’t need more.
By responding quickly with a Direct Message or Comment back with a way to talk to you OFF social media more often than not does the trick. Customers with problems want attention, your social media page is not the place to give it them. Use your social media presence to praise you good customers, use their quotes, give them special discounts for being fans! The more you use social media as a positive place for your customers the less likely the grumps will show up.