If you pay by credit card, your payment could (in rare cases) be denied at the checkout by our security system against possible credit card fraud.
It's a good idea to call your credit card company or bank ahead of time to let them know about the purchase so that it doesn't get declined.
Under such circumstance, here are 3 solutions:
1. Switch to your other credit/debit card.
2. If you have a PayPal account, try to pay by PayPal.
3. Choose “Paypal”,then click "Complete Order"(you don’t need to have a Paypal account to make a credit card payment)
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.