Vacation ruined and harassed ...

DO NOT RENT FROM THEM! In June last year I rented a car from Europcar in Paris and drove it to Bretagne (North of France). We had a flat tyre and noticed that the car didn't have a spare, so I was not able to take care of the flat tyre by myself and had to call them. They sent a truck from a repair center situated 10 km away and instead of fixing the tyre they took the car and went away with it. The guys from the repair center told me that they were not allowed to change the tyre in their location and had to send it to some "authorized repair center". I was left without a replacement car for 3 days (out of 7) and I had to have my friends drive me around (fortunately I had friends with cars). After 3 days someone had to drive me to the "repair center" to pick up the car. After returning the car in Paris and getting home (in NY) I noticed they tried to charge me over 300 euros for changing the tyre and giving my car a "Tour de France" on a truck. I disputed the charge with American Express and the case was settled in my favor. Now they started sending me letters asking for the money and they put me in "collections" with a debt collection company named Progeris. They are threatening to sue me and keep harassing me with letters. If this continues I plan to sue them in the NY small claims court for ruining my vacation, letting me without a car for 3 days and harassing me with "collection letters" ...