You should keep in mind that "with the site" (if you mean FSDT site), when payment is involved, is something completely outside our control, we don't handle payments, we don't know your payment details, we don't have any idea why a payment might be rejected, and you are not even on the FSDT site anymore when you are purchasing.
All payment handling is done by Fastpring (a 3rd party ecommerce provider), and sometimes they might block payment for any number of reasons, most common one the name or address the credit card has been issued from not matching the name or address used for ordering, but also the credit card country not matching the country IP you are located on.
Any number of reasons, completely outside of our control so, when you see the message saying to "Contact Us" because the payment was denied, it means "Contact Fastpring support", for help.
