Disrespectful shop assistant

Yesterday 07/10/2018 my mom and I visited Cambridge food in Town centre Mitchell's Plain, my mother asked for assistance at the bakery section and the female staff member was so irritated and without any answer she just gave a facial expression and walked away. I walked after her assuming she did not hear my mother and asked her I would like to know when the cake was baked her response and tone shocked me as she responded in Afrikaans and raised her voice saying she did not hear and accusing me apparently last week I was rude to her which I did not visit the store the previous week I told her she must be confused as she probably had an argument with another customer. She took the cake and literally just let go of it in the trolley, raised her voice at my mother saying she don't have time for us and walked away. Many customers was also shocked if her behaviour I know retail can be frustrating but this is not how you treat customers as you are representing a company which name you need to uphold. I was totally disappointed in the service we received as the other staff was happy to assist and the store is always neat and spacious to do shoppings however I trust you will address the matter.