Not holding up to there advertising

I went into HiFi Corp a week ago and seen an item with a special price board on it. i requested the item and as the salesman started to write the slip out he said this item is not the same as the board, only the name is the same and not the model number he must get approval to give it at this price. The shop manager says he is will to give R500.00 off the price as its his merchandiser fault and not his. in this case, the price i saw should have been paid for the item, model was not issue. logged it with the head office and he let someone else speak to me, mnow saying a R1000.00 drop but he will not provide the item as per the board in the shop. I have looged at the consumer council and awaiting there response.