Write a letter to the College accomodation office, because I can't work with my roommate anymore

Dear Sir, Madam,

I am writing to express my dissatisfaction with my current roommate. As you know, we share a room and it has become very difficult for me to work because of his attitude.

He always has friends over and it's hard to stay focused on my work while they are shouting loudly in our shared space, especially when it happens almost every night.

Moreover, I have noticed that some of my belongings have been used without my permission, which is despicable. I strongly feel that the conditions to work efficiently for my studies are no longer met, and therefore, I would like to be relocated to another room for the forthcoming term. Needless to say, I am looking for a single room. Because the exam period is not that far away, I will not take the risk of living with someone not concerned by their college results like me.

I look forward to hearing from you,
Loïc

Hi Loïc!

It's quite rude to refer to a person as "it." You should say "he/him/his" or "she/her" instead, or "they/them/their" if you don't know their gender or what to be gender-neutral.
Your letter sounds very formal, but I suppose that was your intention. Well-written. Good job. :)