Personally, I would report both the dealership and the smaller shop to the B.A.R. Even though it was a long time ago, if people don’t report it, nothing will be done. At least it’s worth a shot.
FWIW, I always ask them to save the parts (especially the expensive parts) that were replaced and have the mechanic return them to me. As someone else noted, you can put a small mark on it to make sure it’s your part that was replaced.
