I got negative feedback from a user who refused escrow and a random user I never saw. There should be a way to apply to get feedback removed
If there was no scamming or any illegal action from your account, you should appeal to get that removed.Anyway it does not affect the account without the proper link in the feedback (trust).
Don't encourage that. There is no appeal process... feedback is NOT moderated, except in case of spam (posting the same feedback hundreds of times in a row).