I think it takes a while for the credit to be added to your account after you make the purchases. Someone who participated in the Sound Shapes / Papa & Yo thing would know better than I would, though.
I believe it will post in November. I still think it would be worthwhile to pursue this. The groups would be rearranged a bit, but people buying multiple games would benefit. The accounts will remain active so when the credit posts it can be applied to another purchase.