The only time I ever lobbied for a better grade in college was my senior year when I took Press Law, which was required for journalism majors. It was hard as hell, and the professor (who was head of the department at the time) was known for never giving an A. I will have to say he was one of the best lecturers I ever had, because he could make Press Law interesting.
So I made up my mind I was going to ace that course, and I busted my ass, never missed a class, crammed like hell for the final and ended up with an 88.5 average (90 was an A).
I went to see him and asked him if there was any way he could round up the grade. He told me that if it had been an 89.5, he'd have given it to me, because he knew how hard I worked for it. But he couldn't do it for a point and a half, and I respected him for it. He listened, didn't blow me off and was honest with me, and while I was disappointed, I was OK with it. I still see him a lot, and we're friends to this day.