has anyone, in the same amazon order, bought two different games, that each offered a GC....for example, I ordered Super Mario Galaxy 2, and Singularity, in one order/purchase. My checkout reciept AND email conformation says " Your order qualifies for a 20 game credit".....it says "a"....just want to be sure in case I need to cancel one and make a sperate order. I know they usually are not that picky, but anyone with experience?