I am sorry for the inconvience your having. Please let me try to help you a little bit.
As solution, please, first check http://billing.microsoft.com to see if there are any errors or wrong information. If there are no problems there please try to remove your payment option and re-adding it to see if this helps. If that doesn't work can you please try and changing payment methods (ex: PayPal) to see if it works then and if it doesn't please call 1800-4MY-XBOX and ask for Billing and they should be able to sort it out for you.
To re-add a payment method:
1. Navigate to the Settings Hub and select Account.
2. Under the Your Billing Options panel select Manage Payment Options.
3. Select which type of payment method you wish to add: Add PayPal or Add Credit Card.
4. Fill out the required info and select Next.
Also, please take some time to read this article http://forums.xbox.com/xbox_forums/xbox_support/f/27/t/153161.aspx
Please let us know your progress.