I worked at a toy store this past Christmas season, and by far this was the worst experience I'd had:
It was a busy Saturday afternoon, and nearly all of our cash registers up front were low on cash. The managers told us to announce that we were taking cards only that day, because they were too busy helping other customers to bring us more cash. So most of the registers were accepting cards only that day. My lane was card only.
One woman got up to my register and unloaded her cart, then commented on how we should've put up signs. I'd only rung up about three of the twenty items when she swiped her chipless card at the card terminal. (I don't know of any stores that let you do this so correct me if I'm wrong, but swiping your card on the terminal in the middle of ringing items up is pointless). I finished ringing up every item and gave her the total.
Woman: I already swiped my card.
Me: Could you swipe it again, please? I'm afraid the system didn't register it that first time. Our system is a little slow so it often takes two swipes-
Woman: Are you seriously telling me to swipe my card again? I did it already in the middle of the transaction.
Me: I'm sorry, ma'am. Our terminals here won't accept the card until I've finished scanning every item.
Woman: (Smirks) I'm paying with cash, then. You can't take cash today, can you? But I'm paying with cash anyway. (Turns around to the elderly man in line behind her). Can you believe this? This is ridiculous. Her register is down and now she's making me swipe my card again. I'm giving her cash, see how she likes it. Give her cash, don't use your card.
Woman: (Still smirking) Fine. I'll use my card, then. (Turns around to the old man again) The longer I'm in here, the more Christmas spirit I'm losing. Don't you think they're being grinches?
Old man: (nods a little)
The woman paid for her toys and I gave her the receipt.
Woman: I'm getting out of here before I really start hating Christmas. (She leaves the store, laughing.)
Old man: (Watches the lady go, then starts laughing) She didn't have any spirit to begin with.
Shortly after this, two older women came up to my counter and see my handmade sign. One of the women began cussing me out, cussing the store, and our registers. The managers up front called them to customer service and the woman's friend had to drag her to the front of the store.