Car accident and auto claim?

i was in a car accident in december the other driver was in the middle lane on a 6 lane road 3 lanes in each direction he decides he need to make a right turn from the middle lane into a 2 way street with one lane each way i was in his blind spot in right lane traveling froward both our stories on police report put us where i described but he said i was going to fast when in fact he slowed down to a near stop to make the turn i just had no time to react but long story short his insurance wont take responsibility because he told them i was driving behind him flashing my lights so he changed lanes to the right and that i did the same trying to overtake him so they completely ignore the police report? what can i do please help he is lying and telling a completely different story from the police report i am just lost