Thorntons review: Fraudulent pricing

I just went and got gas at the Thornton's I've been patronizing for six years or more. I have a Thornton's Rewards Card that I use when getting gas. When I looked at the prices on the pump, before fueling, I saw that my 87 octane was $2.609. I swiped my credit card and Thornton's card, then fueled up. The price didn't change like it usually does due to my discount - my discount today was supposed to be $.10/gal. After I finished fueling, I looked at my receipt: It said I received $.10 off per gallon, but it showed the original price as $2.709. That was completely FALSE, and I was cheated out of my discount! I'm really unhappy about that. That is downright fraud, and they should be fined for that! My card number is 173586 (per my receipt), and I got my gas at 6:25 pm on April 3, 2021.