how to be smart enough to use the English and also be polite and to the point?

[jazz]

hi I just need to know that I need to write a letter to the dean of the university asking to change my 'F' to 'w' as it was their fault of not guiding me properly even though I had 3 meetings with the advisor and still they couldn't give me the guidance properly and also no help at all.So am trying to get my grades properly and also so get that I can get back to my studies again.Kindly help as to how to write the letter and be polite to them as I am in too much anger and cannot figure out how to write to them without my anger and be polite enough to make them change my grades and also it would reduce my anger in the letter but also to make my point and my frustration to them.

[Tdol]

Put your basic text up here and people will suggest ways to refine it.