Not happy with their service

Yesterday I was at Clicks Featherbrooke looking for a Sorbet beauty device; unfortunately, I did not find it. I then went to Clicks Blueberry Square, and I managed to find it. On the shelf, the price was not visible, and it was hidden by that big red sale sticker, which says 20% less (I like specials). I took the device with other things I was looking for at the store and went to the till points (Lebohang), where the price escalated. I asked the teller about the 20%, and he told me that there was no sale, and I told him I saw the sale tag. He went to check the tag, and he indicated that it was meant for the other item. I questioned him about why it was placed on the device I was buying, and he said there was no space to put the actual sale item. He further called the supervisor (Brian), and he came up with the story that it was placed by customers, of which there's no way. The senior supervisor, Tshego Mokotsoane, was called, and she put the blame on their staff. They cannot put the blame of their staff on my shoulders, as it was supposed to be placed; that has nothing to do with me.