Outsurance 3rd party claim

I been in a accident on the 25th of March with a client covered with outsurance he acknowledged that the accident was his fault due to him jumping a stop street on the r102 I had contacted outsurance with a claim number given to me by him after 2 months outsurance took my vehicle for assisment which was I write off my vehicle value is 140000 after many calls with outsurance they give me a offer of 20000 to repair my vehicle. Spoken to the client he tells me that he told outsurance to sort out my vehicle just sad how a insurance company that advertises so much treats a 3rd party so bad and with no respect