have also now run in to this issue. Having finally managed to get a payment accepted for AP I got the error. In my case it maybe because it has been a long time since I bought or used AP. So I have sent in a ticket, tracked down the past times I bought AP and put the dates and transaction numbers in my ticket. I also let them know I have changed my password and the dates in the past when I have changed my password.
It has been a while since I felt it worthwhile buying things with AP and now that finally I want to buy AP and get thing in a game i end up with this error instead. I just hope that it all gets sorted out before the tiered spender I want to make use of has gone.
Edit: Should have checked my email, there I find they have happily taken my money but then suspended my account and I have to contact them. Wish they sent a message like that both on the account mail system as well as the external email, it is an email address I rarely use so did not think to go and check it. I also wish they had put a warning when i bought the AP, saying you have not bought for a while so you may have to contact us for us to permit the AP you are just about to buy to be put on to the account.