Lack of customer service and support and incorrect pricing

I was in boxer liquor Diepsloot I wanted to buy a liqui-Fruit Juice cranberry but the price on the shelf was R34,99 but when she scanned the bar code was R38,87 then when i told her that the price wasn't what I saw on the shelf she told me there's nothing she can do since its not her who packed it her Name was Mantwa she lacks customer service and support