Desperately need advice on my 2012 Buick Regal
 

Hello Everyone
I'm new to the forum.Absolutely Love my car and have not had any problems up in till here lately.
I own a 2012 Buick Regal w/ bassist. 2.4 engine
6 speed transmission.My car has 81,000 miles.

I was pulled over by police, my car was impounded.
I watched the young man hoist my vehicle up into the tow truck, However, since I was put inside the police cruiser, I have no idea which gear it was in. I was taken to jail and my car impounded.
Unfortunately this happened on a Friday, So I was bailed out of jail, But couldn't have my car delivered home till the following Monday.
On Monday, the tow truck driver, drove my car in reverse obviously off the flatbed, he put it in park, I pulled it in driveway and parked it.

My car sat for little over a month, in till I could get Insurance on it, (Which is why I got pulled over to begin with)
Does any of you think that my transmission could have gone bad, from sitting for a month an a half.
This is what I'm being told by a garage.
I need a transmission, which is going to cost me
5,671 for a used trans. With I believe a 1 year warranty on parts and labor.
I think the tow truck driver, either loaded it the wrong way. Or somebody took it out joy riding all weekend and fried my trans.
My car was running fine up in till I was pulled over by police, and my car was towed for the weekend.
I just cannot believe, my trans can go bad from sitting idle for almost 2 months.
Any advice Please, I am so upset. Thx Sunshine

Need a little help here,
The tow truck driver used reverse and it worked, you used drive and it worked. What is the reason why the trans is now a problem, not clear.?