Terrible service from Avis

My wife and I were involved in an accident where we claimed through Miway and were given a rental vehicle from Avis. We paid a R1200 fuel deposit and were told that it would be refunded once we returned the vehicle with a full tank of petrol. Miway dealt with our claim beautifully and the claim was settled. Avis then advised us that the rental vehicle was to be returned on Sunday 22/02/2015. This is when all hell broke loose. We arrived at the Avis branch the Sunday morning to return the vehicle only to find that they don't operate on Sundays. Why tell us to return the vehicle on a day that you are closed!!! Then we were told to drop the vehicle at another branch where we would need to pay a fee as it is not the branch that we received the vehicle from (as they were closed!!!). Eventually everything was sorted out and we dropped the vehicle off at another branch without paying a fee and we were told that our deposit would be refunded within 48 hours. It is now 192 hours later and no refund has been done. When we phoned Avis earlier, we were told to wait another 48 hours. I am extremely upset with how we are being treated by Avis and my experience will be shared with everyone I know