Police report anyone?

Why is that the local police departments fail to issue a police report? what good is a complaint number? With both of our recent accidents, we were given complaint numbers, but no report was filed. Now we have to fight with the insurance agencies to not get assessed partial liability for my accident. They finally came up with a decision (after well over month from the accident), and they want me to take 20 percent liability for it. They are assessing me this due to no police report, no ticket issued to the other driver, not enough evidence that she made an illegal left turn, and due to where the damage is on hers they say that I should have been able to stop. Lisa went to take more photos to help support our case and emailed them to the adjustor. If only the responding officer had issued a report, we would have had a stronger case and would have had something to go back to the officer with to have a ticket issue to the other driver to prove that she made an illegal left turn. I am not liking this partial liability law right now.