Cashier swearing at customers.

I went to PEP Mayfield square to exchange an item and I got a horrible service from the cashier Samkelisiwe Mashinini she was so rude, from the first point of sale. She didnt greet she was yawning and had an attitude from the start. Instead of exchanging the item with a correct price she used a wrong price which was lower than the item I was exchanging. Instead of apologizing for her mistake she gave me an attitude and back chats me saying I gave her the incorrect price. she picked it up on the floor, i told her that if the price was higher than the item she was gonna notice,she then tell me that its not her problem im the one who said that price was the one. She had a big mouth carring on as if she at her house talking to her child,the supevisor there or manager Irene she just stood there and said nothing. That cashier doesn't know how to speak or engage with customers. She said I must **** off how can you swear to a customer? Is that the type of service PEP provides to customers swearing at customers?????