So I was in a place known for it's coffee. This is one of those places where you can get a card and put money on it, essentially prepaying for your purchases. The transaction that occurred seemed, from my position as next in line, an understandable but relatively simple miscommunication and yet it took several rounds and intervention from another employee to resolve. (I am blaming neither the employees nor the customer here. Or at least I think it is equal.)
So the customer ordered a drink and then explained that he wanted to add five dollars to his card. The employee entered this into the register, and the total came to seven dollars and change. The customer explained that he wanted to add five dollars to the card. The employee replied that yes, the seven dollars encompassed that request. And back and forth they went. Now, I could see that the customer meant I will give you five dollars to put on the card then from that five dollars, please subtract the cost of my drink. However, while respecting everyone's right to perform their transaction as they wish, I personally would have either explained it differently or done the card reload later. The somewhat amusing thing about the whole thing was that both the customer and the employee were so locked into their explanation that they just kept repeating what they had previously said, like some strange comedy routine. It took several repetitions and the intervention of another employee for them to get to the point where they attempted using different word configurations to explain the situation. Meanwhile the line was increasing.
I read an article recently that talked about how there is a human tendency to talk to someone about an issue, and then, if it does not result in the expected behavior change, we tend to try to talk to them again, instead of understanding that their might need to be a behavior change on our side too. These too guys (who may well have been tired or ill or otherwise understanding challenged that day - not really picking on them) didn't even make it that far. They couldn't get past the words they were using.
Oh, and in the end, they voided the transaction and started again.