My TA letter indicates 90 hours working. However, I worked for 120 hours due to the volume of the students. Now my work is finished I want to let them know by writing an email to the professor. I want to be nice and thankful for the given position.
Note, my goal is to get paid for these 30 hours. I had already raised the issue with the professor before doing the work, and was told to do the work, record my hours, and then the professor would follow up with the head of department.