The guy had around $20 worth of coupons that he never told me he had, so when his wife swiped her credit card before the transaction was complete, when I totaled the order I just hit the "credit" key. There's no going back after that. He says, "I have these coupons" and I went "Oh, crap..." He got all peeved and incredibly rude and condescending while I was apologizing up and down waiting for my CSM to get there to tell me how to fix it. And then I fixed it, by voiding the ENTIRE transaction [they had almost $200 worth of groceries] and re-ringing everything up, coupons included. It took forever, when he could have just gone to the service desk, had them void the few items that the coupons applied to, and then rang those up with the coupons, which would have been way easier for EVERYONE involved. He even, at one point, asked for the store manager. Seriously.
Joke's on him, though -- he's got two near-$200 charges on his credit card now, and the first one won't go away for around two weeks. I hope it prevents him from doing something he really wants to do.
I hate people. Except for the ones I like. But everyone else -- rage and hate.