If you are in college then the scoring should have been given to you at the very beginning on the syllabus. If the grading procedure was followed then you do not have much standing-but if the grading procedure was not followed bring it to the attention of the dean or chairman of that department.

Remember though with both of these solutions there could be ramifications if you have to have the same teacher again. Is it worth that possibly happening? Good luck and do not let this get you down, while grades are important it is the act of acquiring knowledge that is where the true learning comes in and if you learned then celebrate that!