Unfair ****** treatment.

I went to Foschini Sandton city to purchase items on account , I was told by the cashier that I cannot buy without my TFG card even when I have my ID card with me. To my surprise, while waiting to do a new card , a white customer came to buy on account , without her TFG card and ID card, she was assisted efficiently, while I wasn't assisted, and I was told I need a new card (which I will be charged R70 for) I left the store feeling terribly heartbroken by the treatment I got from the cashier. I need to understand why was I treated like that, is this how Foschini treats Black customers?