Unauthorised debits

Upon inspecting my account, I found 4 unauthorised debits totaling almost R10 000 that FNB allowed on my account after I previous told them that my account with the merchant is settled. They advised that I should cancel the card and get a new one to prevent future debits which is what i did and now they've allowed this amount to go off my account. and to top it all, i received NO sms notifications that these debits went off my account on the 18th of March already and i only picked this up yesterday. The private banker is of absolute no assistance whatsoever and makes no effort to keep me posted on the progress. There is no doubt that this account will be closed because as far as I am concerned, this is ********* and ******* and i demand that this be rectified and all monies refunded to my account.