Pathetic service

The worst service ever received from FNB. I blocked a card linked to my business account after I realised that a previous signatory whom I removed from my account was still using the card. And so I called to block it, they told me that it was blocked yet I still received messages of tollgates including charges because there was no available funds. I logged many complaints with the bank, only to be told only now after numerous complaints to fnb that its not their problem and that I should go to court. I mean isn't the bank supposed to protect my account. How is it my problem that their own systems are failing them? How is it my problem that their own staff didn't advise me from the onset that I shouldn't bother blocking the card? Now my Acc is overdrawn by close to R3000 and they tell me that its my problem. How pathetic is that?