Blocked card online purchases

Hai I don't know if one has to be a private banker to be treated like a human or must be famous for things to work out. I had my card ****** and I immediately got it blocked and went to the branch. Everything was confirmed to be blocked and a new card was issued. Yesterday, I got the surprise of my life. Someone is using the same card that was blocked to make purchases online and so far, they have succeeded. I wasn't aware what was going on until I received a notification to approve the purchase of R24 000 and yet that card is blocked. The tellers or so called customer services can't even help you when you have a problem. I would understand if I had left the online purchases unlocked or tap to pay but all of those settings have been closed and blocked off. What's happening?? People can now use blocked cards to make purchases then the bank won't be able to help you and nor even refund you... What bank is safe now or should people go bank to "investing" under their beds???