write a professional well written complain letter (Content Writing / Rewriting )

I would like to write a complaint letter very strong worded and emotional a letter that can show my frustration , anger and disappointment by writing a complaint letter but unfortunately I cannot find the words to do so , therefore I need someone with amazing writing and English skills to help me write carefully structured letter to convey my emotion and frustration
this letter is going to be about my journey before being admitted to the hospital my stay and the events that followed , it's going to be focused on how I was treated and how I felt and how it left me afterwards