Horrible service and paying full price on sowcials

I stopped at Karen Park Spar today, to quickly get the special on the Pampers cat food and Petleys dog food... when I got to the till, the teller ringed everything up. I then said I will give her my number so I can get the discounted price, as the Pampers normal price is R181. And Petleys dog food is R51. The lady rolled her eyes at me, took my number and then said, there is no discount... I told her that the discounted price was on the shelves... she said, "well, what do you want to do" I said, I want the discount please... she clicked her tongue and grabbed the cat food and went to the shelves... after a while she came back and spoke to the manager.. they all rolled their eyes and gave me the evil eye, shaking their heads.. I asked the teller what is going on... she didn't answer me... so then she pushed some butons and rang the catfood up as R149. By this time I was so frustrated I forgot the tell her about the dog food which was on special for R31 and I paid R51... daylight *******!!! sho!! I've never been treated so horrible before!!! I will never set foot in that shop again!! I have the proof of the specials, as well as ny till slip showing what I paid...