Very unsatisfied

It was always a good place to shop at but today when I went to the shop to look for a gift, I found a nice scented candle marked for R18,99,I asked a store employee if the price was correct,whereby he checked the barcode and confirmed that the price is indeed correct. When I went to pay, the cashier scanned the product for R109,99 ,after informing them of the problem they said that they can only give it to me for 89,99.As customer it is not my responsibility to check the barcode or to argue because of their incompetence.