Get a good lawyer. I can’t recall where, want to say Michigan, maybe Minnesota, but there was a case very similar to this were a woman went in to her local garage for a tire change. The tech swapped out the tires and put the lugs on, but did not tighten them.
Needless to say about a mile down the road her tires came off.
The judge actually ruled in the garages favor simply because the service performed “tire change” doesn’t speak to the lugs being tightened. Stupid call? You bet, but in any court case I’m sure they’ll draw reference to this.
For personal reference, I had a shop change out my rear diff cover and fluid while I was on vacation. Picked it up and about 15 miles down the road parked to see the fluid coming out rapidly. Only half the bolts had been tightened. You better believe my truck was towed from my house back to that garage, and then towed back to me after it was properly done. Be assertive and get them to fix that ****.