bad treatment

I am always treated so bad at truworths KOKSTAD because my card can't read. They can't manual punch numbers on the card for purchase but for payment they do.I was there to pay my account and I did so with the same card with no problem, as I was walking out I saw a shirt and decided to buy it. The cashier told me the card can't read I told her buy I just paid 2min ago with the same card, she called someone who asked for my id told them I hardly carry that with when I travel because I am coming from Joburg. we had to argue and fight for me to buy the shirt and my concern is that why only this at kokstad. I used the same card at Mthatha no 1 asked my I'd. I can't take this pathetic treatment for a card that I use all over south Africa on kokstad seems to have a problem. I need to understand why kokstad seems to have a problem or 11 years of my service with you is no longer wanted at truworths. I cannot take this can it be addressed or I should be told not to buy a kokstad .