Launching a social campaign on Google plus is also efdectice. I crucified Verizon on Google + when they totally screwed my account up, and I had a someone personally contact me to handle my case. It got resolved quick.
My wife is very active on Face Book and she started when Brandsmart would not repair our refrigerator under their warranty I purchased. A few post on face book brought them to their knees and they fixed it. Then, Rooms To Go refused to repair a sofa that the arm broke, same thing. They called and came out and took the sofa, repaired it, and brought it back fixed. I had changed Homeowners Insurance because our crooked Gov Rick Scott was making deals with my then Ins. Company. Little did I know, he was making deals with the Company I went with. That Company sent me a notice they were raising my premium because my home was worth $40,000 more than the evaluation of the other crooked company. Little did they know I had a license to sell all lines in the State before I retired, and they were way over estimating the value of my home. This started a war with me, but the Company wouldn't stop trying to screw me. With Face Book, I cut them up like chum and had them calling me to talk. They took off $36,000 of that value in no time.
I now find some of these companies can have your post on Face Book removed from their account, so in some cases you need to post on sites they have no control over like their competitors.