I have every sympathy with you, but the fact you did not use the service does not mean you don't have to pay. It is very important to take note of any cancellation number you are given, also ask for conformation via e-mail. This applies to any ISP, not just AOL.
To be fair to AOL, when you phone them and choose the correct option regarding Customer service and cancellation, you are prompted by an automatic response, "of the importance", to take note of the [Cancellation] number that will be given to you. Regards. j.