Mid/rear Seats Assembly problems of the 2007 Ford Expedition

We purchased a new 2007 inaugural model of the Expedition el. Our vehicle seats 8 and we are a family of 7. One middle seat is generally folded out of use, occasionally used for a child, rarely used for an adult. While on a day trip in March my average sized brother sat in the right side of the middle row seats. Throughout our trip the seat back would not hold to support him and was repeatedly flying backward. This is how we discovered the problem. Were there to be an accident not only would the seat not hold to protect the passenger it could actually cause serious injury or death because of this defect. This vehicle is only a few years old and has been used with normal family wear and tear. It has not been abused in any way. We do not know if this is a failed/defective part affecting this one seat in our vehicle or if there is something structurally unsound in the seat design of the Expedition. We have contacted Ford regarding the issue and they tell us they are committed to safety and share our concern yet will do nothing about it because the new vehicle warranty is no longer in effect. This answer is unacceptable and they are using empty words. My father was killed in a car accident and I have 5 children that I drive around daily. Safety is my number one priority in a vehicle. I am concerned primarily for the safety of my own family but also all those on the road. Please help me resolve this issue with Ford. It is a very expensive repair which I think Ford is responsible for but furthermore they are showing a very careless attitude regarding a serious safety issue which may affect more than simply our own vehicle. Thank you for your assistance with this matter and for all you do to ensure safety on the road. Sincerely, christine ellis.