FNB proceeds to process ********** transactions even when alerted

My wife reported ********** transactions on her account within minutes after FNB alerted her of transactions. The bank continued to approve the transactions which amounted close to R5000. When she called FNB all they did was to cancel the card and say they opened a ***** case and will investigate. This will take about 7 working days while the transactions have been approved and the money is gone. Couldnt they have stopped the payments right away and deal with the ********** activities later? It doesnt make sense at all. FNB has to resolve this problem because they will lose customers. I also bank with them but now i am not so sure anymore, i am planning to change banks ASAP because i dont want to suffer the same. Who has the money to be taken away by ********** during this difficult period of the pandemic?