Wrong merchandise

I was just at Pick n Pay in Uitenhage and wanted to buy toiletpaper. I went go the isle were it was and it was fully stacked and priced aswell. Price on the shelf where it was standing had 2 prices on that was exactly the same R39.99. Got at the till she scanned it and it showed R69.99 i told her the price on the shelve was R39.99 i even went i fetched the prices for her. She said merchandise was packed wrong. Had to go up and down showing her and even took photos of price and shelve. Bad service