Worst was the best. Worked in a large supermarket chain about 20 years ago. A woman got over charged by about 50p and created a huge uproar. Really nasty, shouting, berating us etc I had to call the deputy manager, John. He came down with the store wallet (a petty cash box basically) to placate her.
She gave him hell over this 50p, which had already been refunded, and was saying she was disgusted and would never shop there again.
John got out the wallet:
"Madam, please accept my apologies. As a gesture of good will here is £10. Here is another £10 for the inconvenience and here is another £10 if you would honour us with your custom in the future."
She had £30 in her hand but she would not relent. She started giving off again but this time cursing, saying the whole shop was a disgrace, we were a bunch of thieves and that she would never be back again.
"Fine then, fuck off, there's the door. Call security if she refuses to leave"
And with that he promptly walked off up the shop floor.
Me and the girl on customer services nearly pissed ourselves laughing. Other customers also laughed and told her she deserved it.
It was glorious. Poor John got a formal warning from the manager the next day though. But it was worth it.