Partiality and unequal behavior against disabled person

I am a complete wheelchair bound person and currently teaching in a university.I would like to bring your attention for an act of discrimination that I am being subjected to in the course of my employment as an Assistant Professor in my university.For the last two years this thing is happening with me.This year I was assigned to teach two courses of with eight classes. However just after a month I was suddenly called by the head of the department and asked not to teach one course.When I enquired as to the reason it was told that some students have complained against me and hence such decision has been taken.It was only on my insistence that an email excerpt of a vague complain was forwarded to me. I have since repeatedly asked for copies of impartial investigation report and evidence of such speculative assertions made against me and my teaching method. However the HOD has never bothered to formally respond. Can I take legal action against this?