Years ago they had cards which entitled you to a free sandwich after so many paid ones (maybe 8). When I had a card filled I went to the nearest Subway which had a new owner, an Indian. He made a big fuss over honoring the card, finally did so very reluctantly and wouldn’t let me have a free drink (previously that had been part of the deal). Way to ensure I would never go back there. Maybe the jerk thought I was from a lower caste than he was.
It’s always a pleasure crossing jerks like that off my list. Argue over a buck, lose a customer forever.