2007 MAZDA CX-7 User Comment / Complaint

I bought a brand new mazda cx-7 in july 2007. i took it to the service department on august 9th because of a loud noise from the rear interior. the dealer service department informed me that the noise was from the rear mid seat belt that retracts into the roof. they informed me that the seat belt had not been fitted correctly at the assembly plant and that the seat belt was inoperative. they ordered a new seat belt and replaced the original belt. before taking the vehicle back to the dealer i had been driving my young children in the rear seat on the assumption that the seat belt worked and my child was safe. i am concerned that if the assembly plant can fit a seat belt that is inoperative once and it passes all the plant quality checks, they can do it many more times. how many mazda vehicles have been fitted with rear seat belts that are inoperative?