Jeep rolled away

I have 2015 Jeep Grand Cherokee 4×4. Last Saturday I came home and ran in the house to grab my wallet. I left the Jeep in park. When I came back out, it had rolled down the driveway. I got in and it cranked but wouldn't move. There was a message on the dash that said "service shifter." I had it towed to the dealership. There was a previous recall on Jeeps for rolling away but this issue wasn't covered by that recall. The dealer said it was my valve body that needed to be replaced. $3,000 later, I got my Jeep back. The service shifter light is still on and they said it would be another $400 to replace the gear shift. Has anyone ran into this issue before? I just think it's crazy that a vehicle can roll away like that. Luckily no one was in the road at the time it happened.