Unfiltered Story #198670

I work at a water store in a small town. I decided to balance the register because it’s been a very slow day. I’m half way through and a regular comes in a minute before closing time.
I stopped what I was doing and she fills up her bottle.
(We also have cards that once you buy 10, you get one free.)
She picks the slowest faucet and takes her time. By the time she’s done, we should have been closed for 5 minutes.
She walks up to the register
“Oh, I have a free one.” Puts the card on the counter and walks out.
At this point I was already very frustrated and wanted to go home, and somehow I manage to tell her to have a nice day.