********** transaction on my cheque card

On the 10.09.2015 there was a withdrawal of R1000 on my platinum account that I do not know of. I phoned the Premier help desk and was advice by the consultant to dispute the transaction. She sent me the paperwork and I returned it to FNB on the 24.09.2015. I then got an email on the 27.09.2015 asking if I wanted to cancel the card to which I responded with a yes however this was never done and no feedback was received from then. Today I phoned the FNB ***** helpline to follow up on the dispute only to be told that \there's no point investigating my query as the transaction was done using my PIN and my CARD and therefore its my liability. I mean what the ****!!. The person also imp**** that even if the video footage showed that someone else had withdrawn the money I would not be refund as its NOT THEIR PROBLEM!!! I asked for the video footage and was told that they will try and see if the cameras were working at the time. It seems FNB is not really interested in investigating my issue. I REALLY DONT KNOW WHAT TO DO NOW...I NEED SOMEONE TO INVESTIGATE THIS AND GIVE ME ANSWERS ASAP....."