I know a friend who failed a first-semester course at IIT Kanpur. Although it was a minor subject, the entire process was very tiresome.
He had failed a wonderful Morning Exercise (PE101) course. This course is a very futile course wherein twice a week you are supposed to go for sports for an hour in the evening. The ones who are good at sports are selected for the institute sports team, while the rest are sent to NCC.
The worst part about this course is that although it carries no credits, you fail the course if you have less than 75% attendance. Many top rankers had to stay after graduation to complete the course.
My friends had taken leave to represent India at IOI 2007. She failed to maintain the attendance criteria and eventually failed in the course. It discouraged her a lot and she was worried about losing her KVPY scholarship.
She decided to resolve this issue and approached the dean of student affairs (DOSA), who was also the official instructor for this course. Prof. Prawal Sinha assured her that he will be resolving the issue for her. The procedure was indeed troublesome and she had to run from office to office for months. She even wrote to the directors and key meeting DOSA.
Finally, her efforts were fruitful and she managed to change her grades. She was relieved but the entire process tired her out.