[markem]

As a former college professor (and current adjunct professor), I'll toss in my two centavos.

In the end, it depends on the policies of the school. I have never had a department head overrule one of my grades, but I have had the university administration do it (father threatened to sue). It is unfortunate how your last term went. The way it appears to be represented is that you were not treated the same as others and perhaps singled out.

Your school should have a student services or similar department that acts as an advocate on behalf of students. Go talk to them and bring as much evidence as you can. Most schools, and hopefully yours, will run an investigation independent of the faculty member and department head. At my school, the department / professor was never informed when a grade had changed, they had to notice that the grade report changed for the student involved.

If other students are willing to cooperate to prove your case, then I would assume it could happen.