What s important is that you get it written down. They will have the opportunity to correct any miss communications in their written response. And don t try to document the entire conversation, only the issues that are important to you. Whenever possible, keep it to a maximum of one or one and a half pages. Try to address only one issue per letter.
Nobody reads or understands a long letter with lots of issues.
Put that energy into positive action. First drafts will usually be full of emotion - it is often healing to get these feelings out. Then re-write it stating the facts as you understand them, without the emotion. Learn to identify what you want to see as an outcome. Ask directly for it.