Pathetic service from Avis

On the 30th of August I got a car from Avis (courtesy car). I swiped my car for the deposit of R2000 which was supposed to be a hold on my card. However , the money was actually debited from my account. Upon returning the car on the 19th August I was told I'd get an invoice in72 hours, the car also had a damage. I did not receive the invoice till 31 August. On the 3rd Sept I paid the balance of R4103.45 on the invoice less the R2000 which was debited from my account. However, on the 5th of Sept Avis further debited another R2000 from my account. When I followed up I was told they only see 1 transaction on their side. I sent my statement which showed the two debits. On Sept 16 I received an email from Pabi saying there branch made a mistake and banked my deposit as a sale and not authorization. Then sent them the swipe details to capture. I was informed that a refund would be processed. It's the 23rd Sept today and I have not received my refund or any feedback from Avis as yet. This is an absolute inconvenience. Please return my money ASAP. it's been over a month now since I returned the car.