Car valuable

Hei, i need your help. i hage problems with insurance company, car was on fire, and it was insured by Kasko. Insurance company wants pay very small amount of money, nearly half of price which real worth. i need paper form car dealer or „Takstman”, where is written real market price of this car. Can you do that, vw Transporter T5, long version, med hengefest, 8 seter, automat, 2. 5 disel, 235000km eu til 03. 2020, back doors apon from 2 sides. Thank you.