I was working the grocery store customer service desk one night back in April, and I'm sad to say that I was not at all paying attention to my surroundings. Thus, I was surprised when a normally bright and cheery cashier of mine walked up to me and placed her hand on her forehead in agitation. I asked her what was wrong, and all she could do was gesture to a man who was staring at us. He was middle-aged, with stubble and this ridiculous Sir Lancelot bob haircut. And a hat.
Wondering what on Earth could have upset my cashier so badly she couldn't talk, I walked over and very politely said, "What's wrong, sir?" and smiled.
"What's wrong with you?"
"Did you have a problem?"
"Do you have a problem?"
Tired of this, I cheerily inquired, "Are we playing a game?"
"Are you playing a game?"
"Right, well, apparently we're playing a game. You have a nice day!" And I walked off. Grown men who talk like they're six are not worth my time. He called after me, asking what my name was, but I pretended not to hear. When he followed me, though, I happily told him my name and my manager's name. They really love it when you act completely nonplussed at their threats of calling your manager.

I later found out that he had been making belligerent comments to the cashier and in general was a dick to her, and that's why she was so agitated. He never called in to complain. But seriously, he had such a holier-than-thou attitude while using such juvenile speech, it was completely absurd. Pretty much looking for people to pick on and something to complain about.