That reminds me of an incident that happened to me when I was a grocery store cashier back in 2004.
During the month of March 2004 we had a promotion where if a customer bought at least $5.00 in gas from our grocery store gas station, the customer would receive a coupon for a free 1-litter bottle of our store brand soda. A customer could get a rain check on request, if a certain flavor was not available.
One day a lady came to my line and the first thing she told me (with a mean look) that she knew our promotion had been for more than a week, but we should accept it because she could not find the flavor she wanted (for free) and only comes once a month to the store because she lives more than 22 miles away. And even though she admitted she was told she could get a rain check on it, she did not ask for one but we still MUST accept the coupon.
Of course I had to get a manager to approve it, even though I told her we could not accept it because it was over for over a week. The coupon clearly stated it ended at the end of March. The manager, of course, readily agreed to accept the coupon even though we were told not to accept them anymore.
I scanned the coupon, but I accidentally did it twice and then proceeded to delete one of the entries. Then the lady stands there looking over her receipt and then angrily tells me that I voided off her coupon. I looked at it and even though I remembered deleting one entry, the system actually voided both of them.
I told her I could get a manager to refund her the money, but she declined and took off.