I had a similar problem during undergrad. Once in Advanced Human Physiology, and Statistics. The professors where both in my opinion a little off their rockers! There were multiple times that me and my colleagues had exams with ~10 questions that were marked wrong, but were so clearly right. We would take the text book and try and show how there might have been a mistake, but they wouldn't change the grades. We took it all the way to the president of the university but were just told that the professor has the discretion in grading.
Side note: Both professors where fired after that semester!
So, chin up! Things happen, just work your hardest and good things will happen if its meant to be.