Transmission Failure problems of the 2008 Jeep Grand Cherokee

8/8/12 driving from temple TX to tunica ms (stopping there before continuing on to indianapolis, in). Car gave no issues/indications of trouble. 8/9/12 car would barely go 10 miles per hour leaving the hotel, would stop forward progress of any kind if I stopped, had to put in park, turn off car and turn on again. Had to cross 4 lane highway, but could not get car to move forward fast enough to clear all 4 lanes and middle divider. Took it in 2 green light tries and pulled into gas station (1/2 mile from hotel), gave car a rest, filled gas and same problem when started again. Had to call tow truck and bring to local Jeep dealer, 7 hours waiting at dealer to be told we had an early major transmission failure and it would be 8/13 before it would be ready. Rented a car to continue our vacation. $3,934. 73, transmission repaired, failure occurred at 41,138 miles, Chrysler admits it is an early failure (and states we are out of all warranties), ms dealer states early failure and powertrain should be covered, contact Chrysler when we get home and local dealer here states 5/50000 on powertrain. Chrysler refuses to reimburse more than $1500 which we have not accepted and refuses to acknowledge 5 year/50,000 mile power train warranty. Had this failed while driving at highway speeds it could have caused an accident for ourselves and others. Chrysler has not called to this day the repair dealership to understand why the transmission failure occurred. We were told the oil had burnt by the dealership? there was plenty of transmission fluid, it was just burnt. We are writing to you to bring this potential safety issue with early transmission failure to your attention and to ask what exactly is the NHTSA/dot regulations regarding power train coverage/failures and what recourse we may have. Thank you for any information you can provide.