Unprofessional ad rude.

I bought a car from WeBuyCars and upon its 3rd break down after 6 months of driving it they took it to this car technician called Jag Auto without my knowledge or approval. It cost me an arm and a leg and now this place doesn’t want to give me the old parts they changed after working on the car for a good 6 months ,they sent me an invoice of the car parts they sold from my car without my permission and the rest is unaccounted for. I asked for a detailed invoice on what they bought and changed,it’s day 3 now I’m being given a run around over my car parts and an invoice I’m entitled to.