R1000 missing withdrawal

On the 13th March 2015 at 13:13 I went to withdraw money at one of the ATM's at Fourways mall.I inserted my card and pin as usual and selected the amount,the money was taking longer than usual to come out.I panicked and cancelled the transaction. The ATM indicated that the withdrawal was unsuccessful but I received a notification that the money came out.I was shocked to see the notification but as I needed the money I then did another transaction and the money came out.I went to North gate branch to report this matter and as I was still talking to one of the tellers another customer came to report the same incident and we were both told that the bank will investigate and get back to us within 5 working days.The bank did come back to me as promised but they informed me that my claim has been declined because their ATM indicates that the the transaction was successful.I am very disappointed with Nedbank because I am 100% percent sure that the money did not come out ,as I waited for a while after I cancelled the transaction and I then continued with the second one.I demand that Nedbank view their ATM camera as this has inconvenienced me financially and I want it sorted out asap!