Price change

I was @Home, Gateway mall on 28/02/2020 to buy an item that I was on special , the original price was R699 but then the special price was R299. When i got to the till the item went back to the normal price R699, not R299 as according to the sticker. I was told by the cashier and the manager that the sticker was putted by a customer. They refused to give me the item according to the sticker price.

My question was why a customer will do that and where would a customer get stickers and placed them on items and go but not buy even the item. As far as I know If more than one price is displayed, the consumer is not required to pay the higher of the two prices displayed.

I complain at the relevant department. They have been ignoring my e-mails.