Unauthorised debits on my account

So yesterday i decided to check my balance on internet banking, only to find out there's company debiting my account, i then went to FNB branch in lower long street in Cape Town where i spent my lunch hour waiting in the queue, the nice lady advised me than can only reverse the one payment of R400 could be reversed and the other R400 from the previous cannot be. I need all the funds which were debited from my account to be reversed and reflect immediately in my account because i need those funds and that is my money which was debited without my authorisation. FNB please do not dissappoint me. I have already logged a complaint on the FNB website - 8SV9WPTR.