Hertz Car Rental - Edinburgh Airport - EDI - Scotland - UK

For a holiday trip through Scotland my girlfriend and me rented a car via Hotwire. Hotwire arranged the car for us via Hertz Edinburgh airport. We paid Hotwire for the rental (~230 E for 2 weeks for the cheapest car available), the voucher clearly stated that there would be no extra charges. In the pick up office, the lady asked whether we wanted a theft insurance and a damage insurance, to which we both said no. On the Hertz voucher that had to be signed, it said that there was a charge of 700 Pounds ~ 1000E. When I asked what it was for, she answered that it was a deposit that would be refunded when the car was OK when we returned it.
We returned the car before opening hours, afterwards I called the Hertz help desk to ask when the deposit would be returned. After some mail correspondence and 'internal research' they told us that the car was OK but that there was never a deposit, and that the 700 Pounds were charged for the mentioned insurances. When I told the help desk that we clearly stated that we did not want the insurances, and that the lady at the counter told us that the transaction was just a deposit, they answered that they could not help us and that they would not go into further discussion on our case.

I feel like Hertz purposely misled us to make a better deal for themselves, as an insurance of 1000E on a rental of 230E is way out of proportions from my point of view.

I advice people to be very careful when dealing with Hertz Edinburgh airport rentals, especially do not accept 'deposits' that happen to be insurances.