Side/window Air Bag problems of the 2006 Ford Expedition

I am driving a 2006 Ford Expedition. The other morning, I put my child in the car seat behind the drivers seat. I half entered the car to turn on the engine, as it was chilly out. About 5-10 seconds after turning the car on, I heard a huge explosion. Sounded as if a rifle had been shot next to my head. The baby went nuts. I looked around, and the side airbags had deployed. This was the first time I had turned the car on that day. Luckily no one was hurt. If it had happened on my side, it would have slammed into me pretty good, as well as my child. The dealership I bought it from made me pay to have it driven to them and the rental car. They would not drive it themselves for fear of another air bag deploying while they were driving. This is of course why I wouldn't drive it either. My car is out of warranty. They are insisting I pay for the repair. It is $2500. I think this is a serious situation and am concerned it could happen again, maybe while I am driving. The dealership said since no one was hurt in this instance it wasn't there problem. Do I have any recourse? sincerely, jennifer vestal.