They do this at my grocery store all the time. Black check-out clerk told me last night that I saved $24.85 - I said no, I spent $62.30 for what used to cost about $24.85. She absolutely had no comprehension. Guy behind me said, “Might as well forget it, she’ll never understand.”
Your comment reminds me of the club card at grocery stores. The store just raised the prices a lot and probably are still making money by someone using the club card.