Complaint Review: ITP VOIP Internet Telephone Service

I was a customer of ITP VOIP for over 10 years.  When it came time to cancel the service they charged me $99.95 for the adapter (I had moved and it was missing).  I explained this was an unfair charge because the piece of equipment was 10 years old, was obsolete and had no value. Not only that, the current adapter they had reference on their site I could obtain new for $31.15 on Amazon.  The representative (Leah) refused to let me speak to a customer service supervisor.  I did call back and got through to a supervisor who refused to change the charge, saying only that "that is what we charge for the adapter if it is lost".  

I will dispute this charge on my credit card where I'm likely to get more satisfaction.