Poor customer service from Avis

I hired a vehicle on 9 Aug and am still waiting to even speak to someone to assist with the release on my credit card. I have had to email customer service 3 times to which I have only ever received one response telling me my bank must release the funds. I get told by my bank Avis has not yet sent the instruction to release. We nearing a month! I am still waiting for a response from Avis