Hello,
I noticed you tagged the ticket with system center, and it seems this is NOT related to it. Thus, here's the possible solution for your reference:
Resolution
When you select Pay Now in the Billing section of your Dashboard, you may receive the message Invalid Credit Card Number or Card_Declined. This indicates a problem with the information entered for the card. Double-check the credit card number, expiration date, and CVV. If you haven't already, also ensure that the card has been activated.
Billing address (AVS) discrepancies will not usually cause this error message. However, if the card is from outside of the US, you may be receiving this error message due to address formatting. Pay close attention to the way you enter your billing address differs from the way it appears on your statement your bank. This includes ensuring the separation of Line 1 and Line 2 of the address.
Alternatively, some banking institutions may be screening vendors like Heroku for security reasons and blocking the transaction. In this case, we recommend speaking to your bank about allowing Heroku transactions to be accepted.
Hope it helps.
Regards,
Alex