You can make payment through your Store Credit (Account balance).
How to do? When you place your order, you must select the "Apply Store Credit" option to apply your Store Credit (Account balance) to your cart amount. Then click "Proceed to Checkout", if your credit is lower cart amount, you have to pay the rest on Total amount.
How can I get Store Credit (Account balance)?
You must to buy Credits at https://premiumkeys.com/credit.html
If you buy $100 on your credit, your account will be credited $100