Simply replace the unfilled areas such as "" and "[date]" with your information.
I am writing to you to strongly protest your decision in the [subject of appeal] matter concerning [party concerned] and ask for an appeal. I feel that you made this decision without the [information lacking when decision was made] information needed. Upon more review of this additional information, you would have found that [correct or complete information].
Your decision has a dramatic impact on the educational success of [party concerned]. This could even have a long-term affect on [his/her/their] [life/lives] after school. Please don't make a final decision without all of the relevant facts. Please consider my appeal.