Porr service - I wany my money back

I withdrew money from an ATM today in Sandton. I was not aware that the ATM was not working. AFter completing the transaction my money did not come out, only then did the gentleman (WORKING FOR THE BANK) by the ATM informed me that it was not working. I went to another ATM where I was abl to make the withdrawal. When I checked my historical transactions this evening, I realised that I was charged for a reversal for the money that I wanted to withdraw but didnt come. How is the malfunctioning of an ATM my fault? Why am I charged for reversing mney I never cancelled nor reversed muself? I WANT MY MONEY BACK FNB. I cannot be paying for your team's incompetence.