You could always set up a Paypal account and use an e-check if you have a checking account. As for now, there is no way to buy say like a gift card and punch in a promo code to get gran. We are kicking some ideas around like that but nothing is set in stone. Remember, you can always fight and win battles. Every level up to 10 nets you a free card. And the 15 and 20. Then every 10th after that. Happy dueling.