From: Hellgreens Slave
I LOATHE people with manufacture coupons who try to fool me! I wish they'd GTFO. I'm such a bitch about it, too- when the coupon is expired or they cut off the expiration date first I nicely inform them that their coupon is invalid because of X reason. If they're not nice, I just rip the invalid coupon in half and say, "Now it's definitely invalid."
I REFUSE to take coupons printed off of a computer- because my company does NOT have them. Michael's craft store does because I get those via e-mail, but I work for Hellgreens and we don't.
I think it's more fun when I do an exchange and the person wants to re-buy the item with a coupon... and the coupon is expired and they don't have a receipt and get mad when I tell them policy is they get a store card when they return/exchange without a receipt.