You’re trying to purchase content through your Xbox 360 console that can only be purchased on Xbox.com.
There’s a problem with your payment option.
To resolve this problem, try the following solutions:
Wait and try your transaction later. If a maintenance issue prevented your transaction from going through, waiting for a few minutes could give this issue time to clear up.
If you’re trying to make your purchase through your Xbox 360 console, try using your computer instead. Go to the appropriate page on Xbox.com, find the content you want to purchase, and try to purchase it that way.
Remove any unused payment options (credit cards) from your Xbox Live account. Here’s how:
Under Payment & Billing, click Manage Payment Options. If you’re prompted, sign in using the Microsoft account (email and password) that’s associated with your Xbox Live account. If you don’t know your Microsoft account information, see Microsoft account: Frequently asked questions.
Next to the payment option that you want to remove, click Remove.