2002 2.2 Pontiac Grand Am Timing Chain Broke at 88,000 miles

My timing chain broke last week after I dropped my son off at school. I pulled out of the school and went about a block and I heard a noise underneath my hood and my car stopped. I was in a school zone going about 15-20 mph and I had to have it towed. I was informed that my timing chain broke and damaged the valves and head and cylinder. I was told that I needed a new engine. I had three mechanics with 30 years each experience and the dealer diagnose my car and they all told me that the timing chain should not have broken. There was no sludge or anything. I do change my oil regularly. I guess my question is.I was told to see if the manufacturer would pay for it being that this was so unusual and I have maintenanced my car regularly. Is this a possibilty, because I don't have the funds myself to get my car that is not even paid off fixed. Thank you very much for your time.