Do not trust or use Europcar - untrustworthy and still owe me over $300

Pre-booked and prepaid for Ford Transit (people mover) for 6 days. After getting a confirmation from the agent at the Syd Airport desk that we could return the car to meet a 5 day limit (we originally had the car booked to exceed the 5 day limit by 3 hours), we changed out plans to return the vehicle within the agreed time. The agent confirmed that we would receive a refund of our credit card. Apart from being given an old (and panel damaged Toyota) vehicle, we were effectively lied to. we were told the new Ford Transit we had booked was not ready and wounds fit in the working bay! So to get the most out of about agreed 5 days rentals, we took the old Toyota that was already there. After returning the vehicle on time, we then found out later (after over 3 phone calls and an email to Europcar) that we would not be entitled to a refund, as the origin T&Cs (you prepay you use it tor lose it effectively applied. We are cheated (and still owed ) over $300 *** DO NOT USE EUROPCAR! THERE ARE PLENTY OF OTHER OPTIONS WITH REPUTABLE AGENTS