Rudeness and attitude of cashiers

I am super disappointed it's not however the 1st time but this time I will not keep quiet a cashier by the name of Nokubonga Ngcobo who served me this evening was very rude and doesn't not belong in the service industry. She was rude and doesnt not take being reprimanded in a positive way. She had a quarrel with a customer who was before me and then turned to me with not even greeting and telling me to unload my items from the basket then asked me if I want a plastic but I did not answer because she hadn't greeted wen I greeted her she was then very rude and wen I reprimanded her she then followed with a statement saying I'm stupid and drunk. This is not good for business and she doesnt belong in the front line if she will continue with her rudeness and attitude. I did how ever report this matter to a coloured lady who seemed to be the manager on duty. I would really be happy to hear from you as soon as possible.