It’s kind of wild how much can change in three days.
Anyway. I believe that if you do a chargeback on your payment method, either through requesting a refund for a defective product according to the process that Vannesyra outlined above or through your credit card company, Blizzard suspends your account (because you have told either your government or your bank that the product that you received is irrevocably defective) and prevents you from using that payment method in the future.
So then you have to ask yourself, do you really never want to play WoW again? If you don’t that’s fine, but it’s something to keep in mind for chargebacks and disputes.