Disappointing service

I truly enjoy shopping at Pep. It's one of the most reasonable stores and they're stuff is great however a recent experience left me feeling as if their standards have dropped. I was at their Raisestorpe Branch in PMB shopping for some baby stuff when I came across a pair of baby shoes marked at R3.99. I decided to take the item as it was marked down. When I arrived at the cashier and she scanned the item she tells me it was R39. 99 and now it's R29.99. When I questioned her about why they marked the item incorrectly she just looks at me not saying a word and argues that it's R29.99 and not R3.99. To my knowledge the customer supposed to receive the item at the price it's marked regardless of whether it's marked correctly or not. I eventually left the item as the cashier had alot of attitude. Even if you aren't able to give me the item at that price the least you can do was be polite about it.