Earn $10 in Super Cash for every $20 you spend in Old Navy stores, now through 8/18/11. There is a limit of $50 in Super Cash per transaction. You can redeem $10 in Super Cash for every $20 you spend from 8/25-8/29. Limit one Super Cash coupon can be redeemed per transaction. Don’t forget to use the printable coupon that I posted about earlier this week!