Can a community college allow an instructor to give a student a No Pass grade for no reason?

I have already received my B.A. from a flagship UC and decided to take a course at the commnunity college I transferred from. I successfully completed all work and the instructor gave me a No Pass for no reason. I've tried calling and emailing the instructor, have filed a Petition with the school and the instructor refuses to respond to me, the Dean of the Dept and the Vice-President. He also changed instruction constantly in class for a project and contradicted information in the academic book. The school had no policy during the time I submitted this petition, but has coincidentally decided to create one, now, in case future incidents occur. However, they will do nothing further to get this instructor to explain himself in my case. What should I do?