Pathetic service

On Saturday 13 Nov I bought Dixon earphones at Cash Crusaders in Ermelo. On all the boxes there were stickers "reduced to clear" with the price or R199. When I wanted to pay they said the price is now R329,90 but gave the item to me for the marked price of R199,90. Today, 16 Nov I went to exchange the earphones because the microphone did not work. I explained what happened when I bought the earphones and also that the cashier printed other prices and put it over the reduced to clear items while I was in the store. I pecifically asked the guy at customer service if I will have to pay money in as they changed the prices while I was still paying and he said that no, they will just give me another one. When I arrived at the till they told me I must pay in the difference and even after I told them what they said at customer service, I still had to pay in the difference. The cashiers are very rude and kept on talking about me in Zulu.