Dont know the drivers name. But he delivered to my...

Dont know the drivers name. But he delivered to my job which is a hospital 12/
16/18 close to closing time. The order was actually for a patient and being her nurse I came down to collect her order and pay. The total was 10.06. I gave a 20 and the driver gave me 9.00 back. Not a big deal if it were my money. I proceeded to stop the driver and say you didn't give me all of the change. He tells me he doesn't carry coins and rudely says most people tip and drives off aggressively as I'm left standing outside. However what he didn't know and if he had not walked off with such an attitude, I had a 2 dollar tip in my hand. Again this was not my money and I did not want to come back with the incorrect amount. The driver was beyond rude and I am appalled. I dont know if he was in a snit because the order was called in so close to closing time.