Car in park, but says reverse on console. Won't start, of course

2007 PT cruiser - my car is in park, but the console says reverse. Of course it won’t start. I just had the transmission serviced!

It sounds to me like you have one of two possible situations:
Either the shift linkage/cable (I’m not sure which you have on this car) is in need of adjustment, or you have broken or disconnected transmission mounts. For your sake, I hope that it is the former, rather than the latter.

In any event, you need to have it towed back to the guys who just serviced it.

I think VDC has nailed it.

I doubt very much there is a problem with the mounts, it probably needs to be adjusted. (cable or linkage).

I believe the shift cable gromet is gone at the transmission end of the cable. This happens sometimes on vehicles that have the battery mounted above the transmission. An old battery may leak (sometimes over filled by the owner) onto the transmission causing damage to the shift cable and wiring harness.

You should be able to start the engine in neutral to drive the vehicle to a shop. Be sure to use the parking brake.