SPAR does customers in, check your prices at the till

I saw the price for fish fingers on the shelf R98.99 and took a pack. When the lady at the till rang it up, I saw the price was now R124.99. I asked for the manager to resolve the issue. He fist wanted to see the price on the shelf and when I showed him, he said there is a mistake with the code. I insisted that I pay the item on the at the shelf price but he refused. Is this how SPAR does business?? I think I need to also lodge a .complaint with the consumer councel