Automatic Transmission Torque Converter problems of the 2002 Chrysler Concorde

We purchased 2002 Chrysler Concorde limited in December 2004. The vehicle had 36,000 miles and ran great. Three months later the engine light indicator comes on and the needs service performed indicator. We take the car to the mechnaic ask them to perform a diagnostic check. The diagnostic results concluded that the engine light was on due to code number p0740 (tcc solenoid circuit fault on the transmission, associated with the solanid of the transmission. The mechanic advised us to contact Chrysler regarding the power train that he thought was under warranty for 5 years/50,000 miles or 7 years/70,000 miles. We contacted Chrysler dealership who first said the pwer train was under warranty of 5 years/50,000 miles. The day prior to having the car towed to the dealership called to remind that car was being towed the next morning the mechanic on duty looked up power train warranty and determined that the power train warranty was 3 years/36,000 miles. We had the car taken to aamoco transmisions and county transmission who both concluded that the transmission needs to be rebuilt or replaced and the cost is over $2,000. I am outraged. I am looking for something that clearly provides the details of the power train warranty. I also want to know why the warranty on the powertrain for 2003 models were increased to 5 years/50,00 miles.