Poor customer Service - Not resolving customer complaints

I have been a client of Capitec Bank for more than 15 years and had been mostly satisfied with its services. This all had changed since I had tried to withdraw money from a Nedbank ATM from my Capitec account on 30 September 2020. The money was never dispensed, an ATM receipt was dispensed indicating insufficient funds. However, My SMS notification showed a reduced balanced with the amount I requested. On top of that, I was charged an insufficient funds fee. I have contacted the Branch and logged a complaint. The consultant indicated that the investigation could lead up to 30 days in which they would decide if I should be reimbursed. This is unacceptable since they had all the proof in front of them. I had explained that the cash was never dispensed and My question is how can I be charged an insufficient fee if the cash had been dispensed (which never occurred). I had been to the branch also to enquire about the progress on my complaint, only to be told that Nedbank had still to respond on this issue. And was again told of 30 days waiting period. I now want to know what precisely needs to be investigated??? Also, no one has communicated to me regarding the progress of my complaint. I have to go into a branch and enquire. I also have no reference number for my case since I wasn't issued with one. Capitec please give me my money back.