I came to change 100 rubles. While waiting in line, I remembered that I needed Band-Aids and peroxide for the office. The pharmacist asked if by any chance I hadn't come to change the money. I answered as is. To which I received in response that: "it's ugly."
If I had the opportunity not to change this money, I would not change it, understanding the whole situation. But since such a client has come to you, be kind enough to express your competence. There are different situations in life, and this is not a reason to tell the client in person that he is acting ugly.
The opinion about your employee is not very good