Under such circumstance, here are 3 solutions for you:
1. If you have a PayPal account, please try to pay by PayPal.
2. If you do not have a PayPal account, please select PayPal still at the checkout page & click the complete order button. Then you'll be directed to a page with access to both PayPal and Debit/Credit card payment (for the latter option, you don't have to register for PayPal).
3. Please switch to your other credit/debit cards.
As following steps:
Step 1. Select PayPal (even if you don't have a PayPal account)
Step 2. Click on "Pay with Debit or Credit Card".
Step 3. Fill in your credit card info and complete your order.
Step 4. Download digital product Get download link and password.