Blocking of Discovery credit card without requested - bad attitude and spite

I called the FNB ***** line for assistance with a transaction that went off my Discovery credit car. A female (unfortunately I didn't take her name down but I am sure that the system has logs of who logs in on your account) took my call the morning of the 25th April 2019. After giving me a mouth full and saying that such a small amount R179.99 that went off my account is not that bad!! I was furious and subsequently asked her if she's ever gone without food? Things just escalated from there and I specifically asked her to leave everything and not do anything. Imagine my surprise and embarrassment when I got to Woolworths late that evening and my card was blocked by her!!! Zero communication and directly in contradiction to why I placed the call. I never asked her to block my card as I was inquiring about a transaction that went through. I feel she blocked my card out of spite and that she has race issues due to her attitude and the way she spoke to me!!! Is this acceptable behaviour by your staff?