Unhappy customer

My mother had visited the checkout store in unit 12 and I am ashamed to say that i have been shopping there for more than 15 years. In all of my years I've never experienced such terrible service as one of the staff decided to laugh and talk about my mother in zulu thinking we do not understand what she was saying. Customer service is very important in any rerail store because i myself work in this field so i know how i need to be treated as a customer. Management should teach their staff how to behave with customers because i have never had this problem before

Thank you.