Misleading prices

I went to Woolworth campus square I saw meat with price for R74.99 p/kg save R15 I bought two packets when I was checking the slip later I saw they have charge R140.98 and R137.68 I went back to Woolworths for refund or return meat they said there is nothing they can do it is my responsibility to check correct price and because I have bought the meat at 11:03 and I am only returning at 13:50 it is out of room tempture I ask them why the price of p/ kg is the item of 2kg the store manager said there is nothing wrong with their prices.I have returned the meat same day and sealed it is not written anywhere that customers cannot return meat I am shocked with the service from Woolworths CAMPUS SQUARE.