Urgent(admin's email and whoever important)

I am that guy whose name is not in the new roll no list(no back in sem 1 and course registration was done on time). Today I went to Admin window they asked me to write an application but when I went to do that they closed the window and asked me to come tomorrow, I am thinking to write email to Admin and any other authority. Please provide me email IDs of all those.

And guys please let me know if anyone else is also facing the same problem. Rn my mental health is fucked up