I don't think you have characterized the problem accurately (or at least completely). The coupon allowed you to add dozens of games to your cart, then applied t

I don't think you have characterized the problem accurately (or at least completely). The coupon allowed you to add dozens of games to your cart, then applied the $20 off to each individual item instead of just one, or against the total. It was a logic problem in applying the coupon on the server side.