unauthorised transactions

Good day so FNB assisted me the other day however the problem persisted. The transactions at tollgates continued and FNB charged me an additional R500 for all the unpaid transactions. when i called, a request was logged but declined. when i called i was told that this is because the reversals a gesture of goodwill, therefore FNB cannot do reversals twice. Surely something is wrog with this account, how is it that a card that is blacklisted is still being used. i remain frustrated and i am considering finding another bank. This is such an inconvienience, my account is yet again at a negetive.