I have been trying to pay for Apple Development Program membership as well. Unfortunately, my payment does not get through. It does not deduct any amount from the card and the thank you message says they will inform me in 2 days. This has been occurring for a month now. I have tried 2 different IDs. One of the IDs is US based and the other is Kuwait based. I have been sending them emails back and forth. No luck.
Now I have tried one of the few possible solutions I read in this post:
1. Added payment method to the account.
2. Paid for a random application in my iOS device.
3. Attempted to pay $99 for the membership.
No money was deducted and I think they will not respond to me in 2 days.
Note that the random app I purchased from the iOS store was purchased (money was deducted), downloaded, and is functional in my iPhone. However, when I checked my purchase history in iTunes; it was still pending. Now I am waiting for it to get approved so I can get the order ID of this app purchase and send an email to the support for their acknowledgment that I have used the same payment method in iOS store and for the membership. I hope this issue gets solved.