Here are some reasons why this may be happening:
This error is usually due to your billing address / zip code not matching in the system with your billing method, so you will want to check this if you haven't already.
It could also be that you are typing the number with blank spaces or dashes, so it may also help to check for this too. You will need to find your credit card listed under "My Account > Billing & Deposit" and then click on "Edit" for the card. Then delete everything from that field and then re-type your credit card number again and make sure there are no blank spaces when typing the number - before or after the number as well.
If you are still receiving this error message after attempting both of the solutions above, please open a support ticket so we can assist you. (When you contact support, please be sure to mention that you have also tried both of the above solutions so we will know that you tried this already.)
We tend to answer most support tickets during normal business hours: Monday to Friday, 9:00 am to 6:00 pm (EST). However, we're constantly monitoring tickets, and we'll address urgent issues on nights and weekends, too.Open a Ticket