If your billing issue is any of the following :
You should contact our payment provider (CCBill) directly : CCBill Billing Support. We have no direct access to your financial information, and would just send you back to them if you contacted us.
The only reason to contact us for Billing Support is if you've successfully paid for content but are somehow unable to access it, and/or the content isn't showing up on your "My Content" page.
If that's the case, please submit a report and select "Billing Problems" as your reason.