Disappointed

If i could i would give a 0. I'm shocked to find out that my very old card that is blocked/replaced is still able to make an online purchase. A blocked card. How is that even possible. I called the bank and they told me that it's not possible, took proof to the branch but they couldn't give a straight answer as to how it's possible. I'm disgusted as the service the call center gave me because according to her it was basically a lie, that's why i even ended up going to the bank.