FNB Customer care of NO assistance

On 28 March 2019 @ 4:17pm I withdrew R300 from a Standard Bank atm at an Engen Garage in Kempton Park (Standard Bank Terminal STDAC309). I immediately received a message on my FNB app indicating that the R300 had been deducted off my FNB account but no money was given at the atm. The atm then displayed a message on the screen reading "A transaction error has occurred. Please wait while we update your account". I waited and waited and eventually my card was returned but not my money. I inquired at the managers office and he indicated that the atm was giving problems but it should take an hour or so for the money to reflect back in my account. Nevertheless, it is almost 3 weeks later and still the money is not back in my account. I called Standard Bank and we exchanged a few emails, upon which Standard Bank said that FNB needs to contact them to confirm no money was received and then Standard Bank will correct the mistake. The slip from the atm shows requested amount R300 and Dispensed R0. I have contacted every FNB number I can find online, I have sent 17 emails to customer care and NOTHING !!! I am being ignored and no-one is correcting this mistake. Can someone please resolve this issue and have my R300 reversed.