Poor service from Discovery Bank and their agents

On the 8th April I was involved in a car accident and thus was required to rent a car. My insurer, Discovery Insure pointed me to Avis. I went to the Avis Gautrain branch, filled out the paperwork and swiped my Discovery Credit Card (received a slip) and R1500.00 was placed on hold. Contrary to what various Discovery Bank agents have told me, the money left my account and my available balance decreased by R1500.00. On the 13th May, I returned the car to Avis and they said they would contact the bank to release my deposit. Today is the 29th May and I am yet to receive my deposit back and see my balance increase. I have spoken to multiple agents, who either said they would escalate and contact me back, said they would call me back at a certain time with feedback of who simply just put the phone down on me. Three key role-players who either failed to provide me feedback by the time they stated or who simply put the phone down on me are Goipse from the servicing department, Kingsly from the escalations team and Girshwin from the social media department. I had a heated conversation with Girshwin where he told me I was wrong and didn't know what I was talking about and that the money could not have been taken because it does not reflect on any statement. He further told me, that a holding deposit does not reflect on a statement or recon so he and Discovery Bank would NOT help me with my matter because I didn't have proof. I sent him a picture of my receipt but he told me it doesn't match his records. Not sure how a receipt with my details and card details don't match their records. When he decided that he wasn't going to help me, he put the phone down. Before he put down on me, he told me that a holding deposit is only valid for 7 days if not banked with the merchant and thus it was returned to my account on the 15th April. Not true. On the 20th May, Avis emailed Discovery to release the deposit and on that same day, Ayanda stated it would be released. Tell me, what rental company would let their cars out for a month but only have the deposit valid for 7 days??

I am an avid Discovery member, holding a variety of products with them however this latest interaction has left me with a sour taste that I am probably going to be moving away from Discovery as a whole.