Card not Authorised

So, on Saturday i went to FNB clearwater to collect many card. I was assisted but not told that the card is cancelled here i am trying to use the card to make a payment and the embarrassment of been told the cards declined. Why didn't the agent at FNB clearwater advice that the card is canceled and just let me walk out thinking all is in order. I'm so disappointed at the service i received and the withholding of important information.