I wish there were an official appeal process. It would be easier than searching everywhere for help which might not come. I haven't received a response to my message in hours, but the resubmitted file was rejected within 10 minutes. :/
I am having the same problem with the newest version of Not Enough Items. I Dm'd the guy who rejected my pack, but I haven't received a response. I just resubmitted the pack with a note in the description, but it was rejected with the same generic answer.
My most recent submission for my modpack was rejected because it contains a newer version of NEI than is hosted on CurseForge, but NEI is on the Approved Non-Curse Mods list specifically so that newer development versions not hosted on CurseForge can be included in modpacks. What is the best way to appeal this rejection? Do I just DM the person who rejected it?