Almost embarrassed to pass this on as I am a veteran of 30 years of business travel. Rented a car through Expedia and Thrifty Car Rental with a quoted weekly rate of $119. Returned it two days EARLY and was charged $193. Because I returned it early my earlier contract was voided and a new higher rate applied. When I rented the car I told the Thrifty counter agent I would possibly be returning it early. His response was "no problem". When I returned the car and was presented with the $193 charge I said I would keep the car for the full week. Thrifty would not allow that. Calls to Expedia and Thrifty have accomplished nothing so I will contest the charge through my credit card and likely will prevail. Just wanted to pass this on. I won't be using Expedia and certainly not Thrifty in the future.
I feel for you fixj - our last trip to AZ included a rental car nightmare. I don't know if it's that rental companies really dislike renters who use a 3rd party or if logic/reason/common sense no longer applies to business practices.
My son travels to a different place every week and usually gets a rental car. I will ask him if he has any problems.