Horrible service at Shoprite Rondebult

I went at Shoprite Rondebult just a few minutes ago and what appalling service I received. I was there to collect money sent at the till. Upon getting to counter 2, the lady didn't have a name tag on and didn't reply to my greetings. Okay, fine. I then asked if she has the amount I am requesting and she said that she doesn't know. I then asked my sister to pay so that the lady can check if she has the money. After my sister paid, she closed her till and mumbled. I asked if she could repeat what she said as she was inaudible. She said that she doesn't have the money, then proceeded to help the next client. I asked if she couldn't ask her colleagues if they didn't have. She didn't do that but just continued working. I had to go and ask her colleagues myself, who also showed no interest in my request for assistance. Upon checking my sister's slip, I saw that her name is N. Hlathswayo.

My question is: Do we receive such service due to assumptions of our socio-economic status? We try to support our local business but always get unpleasant service.