A. There is one report you could check to find out why, because there could be an error in that report, it's call CLUE report.
Just like your credit report that contains your credit details, the CLUE report contains your driving history. It is a database maintained by LexisNexis Risk Solutions, most auto insurance carriers provide claims data to it. Inside the report, there is a field called the Fault Indicator, it is where the insurer indicates who was at fault for a particular accident. The accuracy of that indicator is critical because auto insurers determine your premium based on it.
You could request a copy of your CLUE report from your insurance carrier or directly from LexisNexis Risk Solutions, check all parts of it for accuracy, especially the Fault Indicator field.
If you find an error, request a correction in writing. Write both to your insurer and to LexisNexis Consumer Center, P.O. Box 105108, Atlanta, GA 30348-5108.