Time Warner Overcharged Bill.

I signed up for a service for U$76.90 / month but they are charging me U$271.14. When I called them they told me it was a mistake and that it would be fixed in my next bill. I made the payment according to what was instructed me over the phone. (the 76.90 plus fees). May current bill was not fixed and they are charging me a late fee. I've tried phone and email contact without success.