Unprofessional and dishonest behaviour

I just visited Checkers Hyper 14th avenue. I went to buy almonds because if my diet. The price on d shelf was R29.99. I thought to myself Wow !!! That's cheap. I called a staff member Matshiso Sebetlela who took the price of the shelf and showed it to a manager (white mail, bald headed mid 30s. He then took me to the till and showed the price to the cashier . Another manager was called Riaan Van Reyer. He said to me the price is wrong, so I took to the place where the almonds was. I told him that's false advertising and the almonds r R150. I told him I'm going to lay a complaint and he said he can give me for half the price. I said no. He walked behind me and repeated saying he'll give me the almonds at half price when it was on d shelf for R29.99 Photos are proof of the label been removed. If a price is wrong on the shelf is it a customers fault. When I asked the manager to call Matshiso so he could show him the other manager, he said Matshiso is not there. It's not about the price. Its d principle in which the manager dealt with the situation.