Have you tried contacting Billing about the problem? And what method are you using to purchase AP with? If it's through PayPal, you might want to check with them first just in case something might be locking down the account (i.e. someone stole your credit card number and PayPal is using fraud protection to protect you).
If you do contact Billing, try to provide them with as much information as you can. Usually the more information they have, the quicker they can help you resolve your problem, especially since you had just recently recovered your account.
You might also want to check your AP recharge history, just in case any funny business might've happened when your account went AWOL, even though I highly doubt that you might've been hacked.