Door problems of the 2000 Mitsubishi Mirage

I own a 2000 Mitsubishi Mirage that I bought new off the lot. I noticed it had trouble shutting several years ago and it had a loud squeak. About a year later the drivers side door had the same issue for a few months in the winter but stopped in the summer. This winter (2006/2007) the passenger door started acting up once again. It wasn't until around easter that I was with my daughter shopping and after 3 or 4 stops the door wouldn't close. It had dropped about 1 inch so it no longer lined up. When we got home I checked the hinges. The door had cracked around the connection point so the door is pulling away from the hinge. I have taken the car to 3 different body shops and they all confirmed it is rust that caused the failure. I believe this is a manufacturers problem and should be treated as such. I had taken it to the dealership where I bought it several weeks ago and they took pictures but have never contacted me back. They said that although I was within the number of years for the corrosion coverage I was over the allowed miles. Anybody will say the number of miles has nothing to do with it. Rust happens over a period of time. In fact I have seen other car companies that have a time limit for the corrosion yet unlimited miles. If Mitsubishi had this it would still be under warranty. The estimated cost is anywhere from 1000. 00 to 1500. 00 depending on if it can be repaired or has to be replaced. I have tried to call the Mitsubishi customer relations but when I press the number to connect to the complaint department nothing happens and eventually a voice comes on that says "if you would like to make a call, please hang up and dial again". I am concerned to let my kids ride in the car and even if no one was in the passenger seat if for any reason the door fell off while driving it could cause a major accident. At this time I am afraid the drivers door is following the same path yet just hasn't shown it yet.