1) Document everything, every event, with dates. Find other people willing to support your argument.
2) Document how you've addressed with issue with the instructor and not met resolution.
3) Don't make this issue about your grade or any sort of regenge/payback. Approach this from an overall disastifaction of the education -YOU- are purchasing from them. If you have bad/average grades, expect to be brushed off. Be prepared to be labled a trouble maker.
4) Make a clear argument for what you want from the outcome of this .... an apology, resignation, firing, letter of reprimand, simply to be heard, etc... Tell them what you want or you will not get it.
5) Take the issue to the academic dean of the college (or associate dean)
6) If still unhappy ... document all of the steps to this point and file a complaint with the office of academic affairs ... (this really pisses off faculty)
The biggest thing you can do is form an argument, state what you want, create a papertrail and start sticking it in people's faces untill you get what you want.