Air Bag Light On problems of the 2004 Dodge Caravan

I own a 2004 Dodge Caravan. The airbag light illuminated two days ago. Brought it to the Chrysler dealer for repair. The dealer diagnosed the problem as a broken airbag clockspring which is housed inside the steering column and also not covered under the extended warranty that I purchased at time I bought the car new at the dealer. This item controls the proper airbag and horn function and should not "break" under normal driving conditions. I was charged 450. 00 for this repair. I believe this is a manufacturers defect and should be investigated. The vehicle was never in an accident and this part does not require maintenance.