ShopRite complaint: Manager’s attitude and incorrect pricing

I bought 3 jungle oats bars that show if I swipe my savings card, the price is 25 for 3 but the normal price is 6.99 each. I showed the cashier Chereleen that something is wrong cause you charging me more than the normal price if I use my savings card. She saw it and the store manager came Mr Kwayimani. I explained and he refused to reason with me and said that’s what the price says, he didn’t even apologise and left me standing there at the till after I said to him he must use his common sense.
I called another floor assistant and showed her and she saw what I was complaining about. Mr Kwayimani was very rude to me as a customer and had a stinking attitude. I stood at the till for about 20mins and noone could help or assist me. I had to ask the cashier to void the bars.

I’m very upset and waisted my time at shoprite.
I demand an explanation for this.