Earthlink rip-off! They don't prorate. Atlanta Georgia

I ordered EarthLink DSL for a year's contract on May 25th last year. I got bill on 25th each month. In May I called custumer service and talked to a real person after waiting for one hour. They told me that my service started on June 6th, if you cancel it on 25th we will charge you $149.99 for early termination.

I ordered SBC DSL and I canceled it on June 6th, but they charge me $49.99 for June's service. I talked to the service person, and they told me they don't prorate the charge. I have to pay the whole month's service fee without using their service (I have used SBC DSL since June 6th).

The thick is that you sign a year's contract, but no matter when you canceled it you need to pay 13 months' service fee. I don't know how many people know that.
This company should earn money honestly, anyway I will never use this company's service again. Does anyone have any idea to deal with this kind of trick.
Thanks

L.
Whitefish Bay, Wisconsin
U.S.A.