Vonage service

has anyone used them? well DON'T. they are the worst. They refuse to credit your account when they over bill you telling you that you have an internal credit. when you tell them you want them to credit your credit card they won't do it...essentially this is stealing. I think I am going to contact the FTC and file a formal complaint about how they rip you off. I have cancelled my service so I no longer need their "credit" that they so generously put on my account but won't give back to me.
anyone else ever experience this nonsense? any suggestions on my next step before I hit the FTC? I did put a dispute claim on my credit card...damn this is annoying and frustrating..