Uncalled for comments to customer

My sister delayed and was late to check in for her flight from OR Tambo to Harare on a South African Airways flight. When she got there on Saturday 23 September 2023 in the morning around 8am there was a person who was checking in but the people working there refused to help her. I do understand that she was late but what shocked me was that a lady and the man on duty were very rude and unprofessional about it. I'm sure the assumed she didn't understand the local language and one of them was like uyarasa muthuo.. That was uncalled for as she was asking about her options. Customers should never be treated like this in any given circumstances. Just because a person if a foreigner don't assume they won't understand what you say.