Trans will not go into park

Hello Everyone, I have a 2016 Challenger Hellcat. Purchased the car about a year ago. We haven't had any issues until now. The transmission will not go into park. Display shows a Neutral/park fault. We had drove the car all day without issue. Trans shifts great and no other issues. The engine would die if you try to put it in park and release the service brake. We took the car to the local Dodge Dealer. After several hours the dealership called and advised me that the "park actuator" has failed. The service writer said they have seen this before. Since the trans is a so called "sealed unit" that the entire transmission will need to be replaced!!! The bill was going to be just shy of $12,000!! WTH? I have worked in the diesel class 8 field for over 30 years and I am confused that after almost 8 years these units can't be serviced in the field!?! Any help would be greatly appreciated.

Thanks, DL