We've all experienced situations where customer complaints are not handled well.  With the rise of social media, knowledge of poor handling of customer complaints isn't just restricted to the customer and a few of their nearest and dearest who hear tales of incompetence and frustration - nowadays the way customer complaints are handled can attract interest from hundreds, thousands (and in some stellar cases, millions) of people online. The way complaints are handled via social media can make or break your brand. 

The linked article provides some really sound advice about how to limit the collateral damage in handling customer complaints made via social media - so why do things still go so spectacularly wrong from time to time???

I really like point 4 - plan ahead and be solution focused - if you are ready for likely customer complaint scenarios and have prepared responses in advance, then you are half-way there to saving the situation.  To get all the way there, being solution focused is key - nothing will extinguish a complaint faster than you / your team / your business finding the solution to your customer's problem, and doing it quickly.