Possible transmission cooling line replacement

Some background:

Had some AC work done by a mechanic.
During AC work he said he “found” a pinched pipe that carries transmission fluid to be cooled and asked if I wanted to replace it

I told him to leave it be if it was working as before and I would take care of it later. When I picked it up I was told that they fixed it themselves! It was admittedly shady but it was hot and my AC was fixed and working. Despite sirens going off I did not pay it mind because quite frankly it was hot this summer.

The AC still works great.

Recently as I was driving home I slowly rolled over a speed bump before turning into my apartment complex. After I pulled into the parking lot I noticed the car, while still fully on was not pushing forward when I pressed on the gas. I do not know much about cars but I know your transmission and the ATF help to push the car forward. I had just enough juice to pull into my apartment and park (barely).

Tried to put in some transmission fluid using a cone I had, it seemed to take but then when I looked under the car it had just all leaked onto the pavement. Still did not go anywhere obviously.

I ordered some stuff I thought I might need. Some transmission cooling hose, some splash shields (I do not think mine are there anymore) and some clamps. I was pretty sure I was in over my head but wanted to at least try. I might not even need any of the stuff.

I took a look under and it was immediately obvious I was in over my head. Before spending more time/money on this I opted to reach out and see what I am really looking at.

From what I can deduce the transmission cooling line used to be metal, but is now rubber after whatever happened during the AC repair.

I have not even started the car since that day so I do not know how much damage it really caused or could be continuously causing to my transmission even though I am not using it.

What kind of service should I look for/ask for?

Whereas I want to hold the mechanic accountable if this happened on their watch - considering they boned my transmission. I am less inclined to because it was like pulling teeth getting them to replace the compressor with my own parts anyway. They made me swear I understood there was no warranty on the work. Again, AC repair is flawless. But the cooling line they found pinched is less so and I just foresee push back that will go around in circles and justice be damned. Just would not be worth the trouble. Though I am pretty sure that if the cooling line was pinched as reported beforehand my car would not have been pushing forward before I got there. That is just my knee jerk defense mechanism as someone ignorant otherwise though. I could be wrong.

Any help is much appreciated.

Thanks!