Rude teller

I just had the worst experience from a teller at usave Bellville even now I'm still boiling. I bought some stuff there with a R10 Telkom airtime and at this time I was rushing to go visit my friend in hospital. When I was in the taxi I tried to put in my airtime only to find out it's Vodacom not what I asked for. After my visit I went back to usave still understanding that she must have made a mistake but when I get there she first make it my fault I told her I never even used Telkom I mean never. The teller was cheeky gave me attitude another teller had to tell her to give me the correct airtime. She did not apologize just kept on speaking Xhosa to the other teller and laughing as if it was nothing. I was so upset because I had to walk back to the store to rectify her mistake and what I got was attitude. I spoke to the manager and he said he will sort it out and I know chances of that are very slim