Front Seat Belt problems of the 2007 Jeep Wrangler

Was in a car accident. The Jeep was sitting at a traffic light when it was hit from behind by a SAAB 93 going about 30-40 mph. The seat belt did not catch on the Jeep and thus my forehead struck the steering wheel. I was told by the Jeep dealer that with this model Jeep the seats belts do not catch unless they are engaged just right. So because I was in a stopped position and was at rest it would not have caught. I went to the emergency room following the accident with a severe contusion to my forehead. Having said this, the Jeep itself held up extremely well in the crash. The police man on duty said it was what saved me from further harm. I am nervous to drive this vehicle not knowing if the seat belts will work in the future. I also have 3 child seats in this car and worry about those as well. The dealership said they do not check these and wouldn't check it after the accident even though I requested it. The car was in their shop for 3 weeks. Please investigate and let me know what can be done.