Thrifty Car Rental

Everything was fine except we were told that if we could not park around the back upon our return, then we should leave the car across the street in the public parking (Parking Pl. du Tunnel). I asked where exactly if there were no public places available, and was told to just parallel park on the side because the car would be collected early. It seemed strange at the time, but I just presumed that they had an arrangement with the local council. Now I've received a parking ticket for 110 CHF, or a day in jail if it's not paid! Naturally I'm now being told by Thrifty & Hertz that any parking or driving infringements are the drivers responsibility. Thrifty obviously new that they did not have enough parking spots for the rental returns, as they mentioned the parking across the street right off the bat, so WATCH OUT if renting a car from this location.