Bad service at POS by store manager

I was just at Pick 'N Pay at Springs Mall to get a 2 burner gas stove, which was displayed with the price of R339.00, but at the till I was charged R379.00, I told the cashier the displayed price, she called the supervisor (Xolie Shabalala) rudely told me I should have compared the barcodes, as I customer I was taken aback because that was not my job, I expect to pay the displayed price, they proceeded to call the store manager ( Xolie zulu), she was informed of the situation, but she told me to take the deal or **** off, I was shocked because it was the second I enquired about a problem and they continued to be rude to me, I bought the stove because I urgently needed it , I don't want any apologies I just want my money back and please train your staff how to do customer service because they suck at it.