Sounds like the sensor for the trans isn't picking up that the vehicle is in park. Unless it isn't actually in park when you are trying to turn it off.............
I believe you have the shifter since it's a '12. With the vehicle in PARK but still running, wiggle the shifter around a bit (while in park - it won't move much), then run the shifter up and down through all of the gears (with your foot on the brake of course). Do this a couple of times back-and-forth. Sometimes those switches just like to get used to their full range.