Mechanical Failure Claim

I dont have many words to describe the service of the above mentioned insurer its totally unprofessional,pathetic and annoying. My car has been standing at the dealership for over a month now due to them delaying the process of fixing it,the initial assessment of the dealership was that i need a new Engine and that Approval took 3weeks for them to approve it now during that 3weeks it was countless back and forth emails ,calls from me and the dealership. After installing the engine it was found that the Turbo and catalytic Converter have failed its over two weeks now trying to get Approval from them for the parts so this is actually my last resort because im totally fed up with their service its unacceptable.