Charter Communications did not honor an agreement made and overcharged my account for 1 year. Simpsonville, South Carolina

In July 2009 I contacted Charter Communications to see about switching my telephone service from Vonnage.  I was quoted a price of $14.99 per month for 1 full year.  I was also instructed to call at the end of the year to see about available promotions at that time.  When I called in July 2010 I was told that I had been paying $39.99 per month all along as I was never set up with the agreed to rate of $14.99.  When I asked them to honor what I had been quoted and asked for credit for the 12 months of overcharge, I was told that it was my responsibility to have noticed and they can only go back 30 days for a billing dispute.  I filed a complaint to the corporate office through the BBB but was told the same thing.  I have learned that even though Charter will quote you a rate for a period of time, they may change it, intentionally or not, and it is up to the customer to catch it or they are out of luck and money.