Disgusting service

So today I went to checkers in Brooklyn Mall Pretoria to do my shopping, I live around the mall and also work there. So to my surprise there was an item which I saw and was interested in because I saw the price and assumed it was on sale so I took 3 units and immediately took a picture of the item on the shelf should I encounter any problems. So when I wanted to pay for my groceries the item scanned at a much higher price and I immediately showed the cashier the picture and requested to pay the price I saw as it was my right as a customer. The manager available at the time was called and she told me that I couldn’t get the item at that price since it was not possible that it would be that price,I asked what should happen because I saw it at that price and that’s what I wanted to pay. She called the stock administrator a middle aged gentleman who was very rude towards me and embarrassed me on the floor in the presence of other shoppers saying that it was humanly impossible to get that item at that price and the manager to together with the stock administrator immediately fixed the price but to my advantage I had already taken the picture by then. I’m deeply hurt with the service that I received and to belittled in the presence of other shoppers was not a pleasant site since I’m a regular at that branch. When I requested to speak to someone superior maybe a branch manager,I was told she’s not in and I was dismissed right there and than. I would like this issue to be rectified and to receive those times at the price I saw since I’ve got proof and I’m willing to email it to the branch manager.