Old parts not returned to clients

I went to kia centurion to change a clutch plate and I paid R8000 for it.When my car was done i thought I'll find my old part in my car but I was told by Yvette that I should have requested for it and she will call me back regardingthat.if you go to vw and fix any parts youll find the old one inside your boot.this not the 1st time struggling with kia when I bought it took them 2months to give me spare keys.When you do service with them no transport for clients