Bad service in third party claims

I had an accident and because both me and the other party belongs to the same insurance outsurance insist that we should cover our own axcess and claim from our own policy they just requested a sctech from me and after that they diceded that without any investigating the scene... why should I pay when I did not cuase the accident and informing me that we should go to small court claims imagine I’ve been a loyal client to them and that’s how they treat they clients so unProffetional for my liking