Difficult to contact

Easy to book car and price was reasonable but the additional insurance most definitely should NOT be taken out through rentalcars.com. This should be done at the rental car desk when picking up the car. The rental car company were going to put €800 on my credit car to cover any damage that may happen. I took out EXTRA additional insurance at the airport as they explained if there was any damage to the car I would have to pay it and claim it back from rentalcars.com. We tried for over an hour to get through to 3 different number to cancel the original additional insurance but the telephone numbers were not answered. I have tried to find an email to contact someone about this but have been unable to do so. I understand now how difficult it would have been IF I had had a claim. On the web site there is a place to leave a comment but when you try to leave a comment, it won't let you.
The only way to dispute this is through my credit card company.