So I had a guy and his family (including several very young children) come up to me with a few items and a coupon. The coupon said that if you paid with your Mastercard, you would get a $50 discount off a purchase of $100 or more. I rung the guy up and tried to scan the coupon, but it wasn't working. I paged for help over the radio, and was told we were no longer accepting the coupon because people had been abusing it. We also had correction signs posted around the store explaining the situation. I went to get one and showed it to my customer, apologizing about the misunderstanding. The customer was upset and demanded to know why he couldn't use his coupon even though it wasn't expired. I showed him the notice again and called for a manager to help out (because at that point I realized he wasn't going to listen to me).
A manager who I'll call S came up to the register. S apologized to the customer and explained that the coupon had been issued by Mastercard without getting it approved by us, and as people had been abusing it we couldn't accept it. He said that customers on our frequent shopper program had been emailed a notice explaining the situation. All he could do was give customers our corporate phone number and have them call in.
I can understand being upset at not being able to use a nice discount coupon like that, but the customer completely lost his head. He demanded to see a manager, and when S told him that *he* was the manager he wanted to know who was the *head* manager. S explained that there was only one guy above him, but he wasn't in the store and couldn't help. The customer demanded the District Manager (which made me go "WTF?"). Cue a loop of angry shouting by the customer, demanding to know why S couldn't fix things for him, and S trying to explain that this was a policy set in place by corporate, which he was not allowed to override. (Seriously, we're a national retail chain. Did this asshole really think one manager at an individual store had that much authority?) The customer also demanded S's full name, and S told him he's not legally obligated to tell him, which of course made the jerk madder. Finally he shouted that he wasn't going to be shopping with us any more and wasn't going to buy the items, and turned to leave the store with his wife and kids.
Now, at the very beginning of the transaction, before things went sour, the guy had opened a large bag of candy and given it to one of his kids. But after his tantrum, when he was about to storm out of the store, and I told him he'd have to pay for the candy or it would be stealing. Me and my big mouth. Now he and his wife were screaming that I was accusing them of stealing. Which...they had technically been about to do since they'd clearly forgotten about the candy. My manager apologized, but insisted they'd have to pay--which they did, though not at all gracefully.
Oh, but things got worse! As the manager was trying to apologize AGAIN, the customer turned and said that he had to back off and get away from him. S stopped sounding so apologetic at this point, and said with a little bit of annoyance, "Sir? I'm just trying to apologize."
"I don't want your apology! Now get away, you're in my face like you're threatening me!"
Wow. The whole time S had been talking, he'd had his hands clasped in front of his stomach like he'd been pleading, bent very slightly at the waist. His body posture had been very submissive the whole time. We were both pretty shocked. It was even more ridiculous because even though the angry customer was short (maybe about my height, and I'm only 5'3"), S was maybe only 2 inches taller than the guy, max. I think the guy was being a dick because S was black, but that's just a guess.
At this point S told the guy that if he was going to speak like that, he could actually have him ejected from the store. The dude and his family finally left the building, dragging their kids along behind them. What a great example to set for his children! When you don't get your way, scream, shout, verbally abuse, and threaten!
TL;DR: Guy wants to use a coupon our corporate office has banned, doesn't want to believe that a lowly MOD at an individual store can't override the dictates of corporate, huge tantrum ensues.