2000 Isuzu Rodeo transmission problems

Dt: the vehicle was parked with the gear shifter in the park position and the key was not in the ignition. Consumer's son, who was 2 years old, was sitting in the back seat. Child was not restrained in a child safety seat. Consumer went inside the house for a minute and when he returned the car rolled and crashed at the end of consumer's neighbor's yard, striking a tree. There was a moderate incline in the driveway about 45 degree angle. There was substantial damage to vehicle.

When shifting gears transmission slips to a lower gear. Consumer notified the dealership. The gear shift didn't go into gear on occasions. The only way to check the gear is by the speedometer. Dealer stated they didn't have the unit in stock and there were none in the u.s. *nlm