Complaint about AVIS

I rented out a vehicle with AVIS on 24 August and returned it on 26 August. There were no damages on their vehicle, only a punctured tyre. I signed off for the vehicle and flew back to Cape Town. Two weeks passed and I didn’t get my deposit so I had to go back and forth to their branch at CTIA. Eventually they returned my money then I had a minus on my account. When I went back to their branch at CTIA I was told I damaged the vehicle and I have no knowledge of this, I never even signed for anything when they took the car back because we checked the vehicle and there was no damage. I went again about two weeks ago seeking a report of this alleged “damage to the vehicle” and a copy of my invoice which I never received and I was told the car was rented out to some Italian guy or something on that particular weekend. I asked the consultant if they clone vehicles because, luckily I took pictures of the car when I took it. They can’t even find my booking anywhere on their system. I am really disappointed with AVIS, I want my money back, I want my invoice and I want proof of this damage I allegedly caused to their vehicle.