Incorrect Pricing - staff unaware

I went to Tile Africa on 1st July and was quoted R109 per square meter of a tile I absolutely loved. The salesman advised they had plenty stock and even showed us a display where they had made up a mixed pattern. I came to pay and arrange delivery for 130 square meters of the tile to be told it was incorrectly priced. I even have photos of the tiles, price and display I took on the day I was there. I refuse to pay 3 times the price for the tile. Not acceptable!!! The excuse I was given was that they were in the process of changing the display. That would be fine however the salesman at NO POINT advised of the incorrect pricing and the tiles they say we're the ones advertised are not even that price.