Rude Pep staff

I went to pep cell at Mall of the South to buy Spiderman headsets for my son the price displayed was R99. 00, when the cashier "Lethabo" scanned the item it was R129 then I told him that it's not the price displayed and as a customer I have to pay the price that I see displayed. He called "Nolwazi" but she was so rude. She just said no I won't pay R99. It's either I pay the price scanned or I leave the item.