Bad customer service with a very distasteful attitude from a cashier (Khethiwe)

There's a cashier who has a very ditasteful attitude that doesnt sit well with me. I normally buy from woolworths food at that filling station and I just never experience a great service whenever i'm assisted by Khethiwe. She is extremely rude, today when I was there I decided to change a packet of chips while I was at the till point, she then became very impatient with me and said something that really madev me angry. She told me that I am wasting her time, customers are waiting for her ( sisi mawenze ungimoshela isikhathi ama customer amile) I got annoyed and she didnt even see the need to apologize. Firts and far most, Khethiwe wanted a job, but er treatment towards customers is very bad. It's a concern when a person doesnt see anything wrong with such a behaviour, my experience at the quick shop has just been an inconvenience.