Nedbank Phumulani Mall unable to refund my cash

Nedbank phumlani mall tembisa unable to refund my money,i went to withdraw money at their ATM on yhr 11th of Sept,when the money was supposed to be dispensed their ATM went offline,when i lodge the complain they said the money was dispensed,refusing to provide with footage to support their statement,i even attached the picture i took of the ATM,they closed the call and they said they are not able to assist me further,i am thinking of going the media and expose them.i want my money back