Calling out demeaning words towards customer

There was special on toys at CNA. When I got to the till I know from experience that it would be my responsibility to check that the products were correctly discounted. The one toy: hotweels was R300 now R50, but it was NOT correct on the System. The cashier called her senior to correct the mistake, all the other toys were correctly discounted on the system. The senior was speaking in a language not understandable by me while correcting the mistake on the system. After paying I checked the slip, there were various discounts loaded ranging from R0.16 to R42.49 attached to all the products on the slip. I asked the cashier why the discount of R250 on the one toy was loaded like this, and of course if this amounted to the correct R250 that is supposed to be discounted. The senior personnel member came rushing in an were very rude, grabbed a calculater and work out the amount. She handled me as if I were stupid, even though I did not understand their system. As I was walking out she called out in a foreign language to me with the word \stadig"which means SLOW in english in front of all the other customers waiting in line! This person is unfit to work with customers!"""