I rented a car through Priceline with Thrifty. I was guaranteed unlimited mileage. I was told that I had to pay 60 dollars once I picked up the car, 20 per day, because I was going to the DC area. We actually went to Arlington VA. I called Priceline and spoke with customer service. What a joke. The only think they do is delay and hope you die! They have not done anything but continue to say they are working on it. How difficult can it be. They guaranteed me unlimited mileage without any conditional charges for destinations. Pretty clear cut.
PS I am on hold for the 4th time with Customer Service as I write this. 21 days and waiting. Not going anywhere!