Bad Customer Service

Today myself and my husband bought some groceries and stationary at Shoprite, after watching the teller scan 3 sets of colour pens 4 times and advising her that she just did that she continue arguing he is wrong. She had a bad attitude and called the supervisor who both spoke in their language acting like we are stupid. I then took the slip and counted with them 4 items of which only then they took the one of set of pens off, at no time during this did one of them apologised. We then called the acting manager of the store and my husband made him aware of what just happened and he apologised on their behalf. I understand people make mistakes and that is not issue but instead of correcting what she did wrong she kept arguing.