2005 Chevrolet Trailblazer transmission problems

I parked a 2005 chevy trailblazer rented from budget rent a car in the hotel parking lot where myself and my fiance were checking in to. I removed the key from the ignition and went inside. Approximately 30 sec later the car rolled down the hill in a large arc (due to the steering wheel being locked) and collided with another vehicle. The car was in neutral. At that point I put the key back into the ignition and found that the key could be removed while in neutral, which caused the car to roll.

Normal driving, I noticed some liquid spots on the driveway. After inspecting, I found that the transmission oil cooling line is corroded through, leaking transmission fluid. My chevrolet trailblazer has less than 60000 miles and is 5 years old. One line is clean, the other is corroded beyond repair. Transmission oil cooling lines have to be replaced.