I've had the same experience. Now, I try not to leave the store until I've read the receipt. Recently, I had an Ace Hardware Rewards coupon for $5.00. Fine print said you had to spend $25.00. Well, the items rang up a few pennies short of the $25.00, so she (without telling me) charged me $1.00 for a "fastener" that I had not purchased. I went back to the store & picked up a light switch & said I want to exchange this for the "fastener" that I was charged for but did not get.