Unnaccepable customer service

I leased a car through Liquidrand and after two months I experienced a technical glitch with my account and I was told had 48 hours to rectify this. In the process I was instructed to return the vehicle before the 48 hours. I obliged but still sent an email to Angelo and how disappointed I was at the service. I revived an apology email offering me 50% off my next rental (acknowledgement of bad service). This took place in April and I have since been chasing them to refund my deposit. To date all I get is excuses and that the delay is with Hertz (Arcadia). I have received nothing but bad service from Liquidrand. I have kept all correspondence incl failure to provide contact details for a senior person.