2011 Kia Sportage drivetrain & axles problems

I was park in the parking garage of my work place. The time was between 7:10am to7:15am. I put the car in park. I stepped out of the car to get my purse and other bag on the ground. I left car on cause I was listening to a song. I was looking for an app on my phone to see what song was playing. I then walked around to other side to get a book that was in passenger seat. I walked back to driver side stood there a minute or two still searching for app on phone all sudden my car starting to roll back.

Tl* the contact owns a 2011 kia sportage. The contact stated that the vehicle would lunge forward, slip gears and remain in fourth gear sporadically and without warning. The contact would have to turn the vehicle off and restart in order for the vehicle to perform normally. The vehicle was taken to the dealer for diagnosis, but the cause of failure was undetermined. The manufacturer was notified of the failure, but denied any assistance with repairs to the vehicle. The vehicle was not repaired.