Incorrect pricing on Woolworths cheese ignored

On Friday night my friend & I went to the Engen Woolworths in Linksfield to get a few snacks. When it came to paying for the items, I noticed that the cheese which had been marked on the shelf as R35 was rung up as R55. I told the teller that the price on shelf was R35. We went to check and the cheese positioned in front of the R35. He then said the price was for a 250g cheese & not a 400g. I had taken the 400g cheese which was listed as R35. He refused to adjust the price. I called the manager who told me he doesn't care & is not interested, it doesn't work like that as in if the cheese was above R35 but is actually 400g & R55 that's my problem. I know that according to the CPA if the cheese was priced above the R35 mark, that is how much I should have paid. It is the responsibility of the store to make sure the items are placed above the correct prices and grammage. I have photos to prove there were other 400g cheeses above the R35 label. How does this man & his staff not know the law? I am speechless& would like someone to pls get back to me on what will be done about this