I have done that once before...and only once. I won’t go into the details of how badly the meal and service were, but here is what followed.
I was having dinner with my sister when she was a student at UNC. The “waiter” followed me next door to a bookstore and asked if there was some problem with the service.
I said, “Service? What service? It was practically nonexistent”...and named a few examples of WHY it was so bad.
His reply: “But sir, this is how I earn my living!”
I looked at him square in the eye, paused, and said: “Perhaps you should consider a different line of work.”
He said nothing, turned, and walked out of the store.
Perfect!