Recently I hired a professional cleaning company to clean my home. We agreed on the price of $79. They only take cash.

So they came and cleaned and then it was time for them to get paid and leave. I handed them a $100 bill expecting $21 in change back. They said they don’t have any change at all. I only had a $100 and a $50 so I could either overpay them by $21 or underpay them by $29. They didn’t do a particularly good job at cleaning so I didn’t want to leave a $21 tip this time.

Eventually I found some coins and managed to pay them $73 and they left angrily.

It seems to me like if your business only accepts cash then you ought to have change. Yet they acted like it is my responsibility to have exact change. Which is it?