Hmmm....So what your saying is that you don't want to pay for the account anymore? If you have the account you can just go to the worldofwarcraft homepage and log in and cancel the subscription through account management. If you don't have access to the account management, then you can just cancel the payment by calling your credit card company and telling them to stop paying for it. If you don't want to do that, and you have the CD keys, just call Blizzard saying your account got hacked, and give them the CD keys that you used for the account, and then try to get the account banned to stop paying for it.
Thats all I can think of =/
~Dark_Angel