bad service at picknpay greenstone

I went to purchase a tv from picknpay greenstone .I saw the Tv I wanted with the price displayed for it I asked someone if it was correct price and I was assured it was the correct price I gave it some thought and went back again and again I was assured by more than one person that that was the price so I agreed to take it when it came to paying at the till they told me I had to pay R600 more than the price I saw and I explain to them that I was assured it was the price on the shelf and rudely by the head of that department I was told I can get another tv for that price which I told him it's not what I wanted for the price I saw eventually I called his boss which didn't seem bothered by the matter or the way it was handled and proceeded to tell me cant sell it to at the price I saw .this is not the first time I have gone to this branch and prices have been completely wrong on the shelves and corrected or given to me at the price I saw .I feel the service level in that shop is very low and unhelpful aswell as things are not well organised and don't feel customers should have to suffer for there incompetence