No response from Card Holders Dispute

In August 2017, my Nedbank account was debited by First Car Rental for a transaction I never approved (I did not rent a car with First Car Rental since January 2017, the account was settled at the time). I therefore opened a claim with Nedbank Card Holder dispute immediately, and have been battling with them ever since to get my money back. They don't even reply to follow up emails. I therefore suspect that Nedbank actually stole the money from my account or were complicit with First Car Rental in doing so. Otherwise, why are they not crediting my account back? I asked them to provide the debit authorization from First Car Rental, and they have been unable to do so. But they have not given me my money back either.This proves my point that something really ***** went on, and that Nedbank are complicit.