Cartrawler/Goldcar review: Car hire/overcharged

I hired a seat Arona automatic from Goldcar via Easyjet, commencing 5th October 2023 to 12 October 2023, I also puchased the Premium Axa damage refund insurance. The confirmation document stated that it was not necessary to take out any other insurance, however at the Goldcar desk on arrival at Alicante airport to collect the car we bamboozled into paying a deposit of 390.50 Euros to cover any damage to the car caused to the car whilst in my possession including any scratches over 2 centimeteres. I explained we had Axa insurance and presented the paperwork, but the male representative informed me that there was no way that they (axa) can insure a car that they do not own, I was alarmed to hear this, so I just paid the money. Part of the fee charged was for ensuring I re fuelled the car to full which of course is fair, and I did comply with this before returning it, (I have the fuel receipt) and my deposit for that has been refunded to my bank account. My complaint is that because of the extra insurance charge requested by the Goldcar representative at the desk, it cost around £500.00 to rent this car for seven days which I think is extortionate. When you are at the desk at 23:00 after a long day travelling and are faced with the threat of not having your pre booked transport released, you do not feel in any position to argue you just pay the money! I would be grateful if you could look into my case to see if there is any refund available to me in regards to this please