Letters / How to write an appeal letter for admission into University [7]

Hello there,

I recently applied to the Singapore Management University and was unsuccessful. I know that chances for a successful appeal are slim, as such I would like to make the most mine and am seeking advice as to how to go about doing that.

The appeal is being made online through an account with the school and all it says is to state my reasons for appeal in less than 1000 words. I'm not sure how to start and what to include.

I went through the threads on here and have found several different styles. Which would be best? Do I have to make it really formal with "Dear Sirs/ Admissions Committee, " or just cut to the chase? What should I avoid and what should I do?

I have average grades and did not attain any leadership roles from Poly. I really want to get into a University.

I look forward to hearing from someone soon. Thank you for reading this:)