I booked a car through them, but I wasn't given a car. They refused to give me my money back, coming up with all sorts of excuses (they had to cover their admin costs, it wasn't their responsibility, I hadn't turned up to pick up the car (I had proof that I had) etc). Eventually I went to a small claims court. I got 100% of my money back plus costs. Don't let them get away with it if they do the same to you.