Generally, you can appeal any punishment you get ingame. By the looks of it your punishment is invalid, but I'll leave that to be judged by the handling admin, if you decide to post an appeal. Personally, I wouldn't appeal the punishment, since the punishment was over a year ago and doesen't affect your current status inside the community at all, but it's certainly up to you to decide, if you want it removed or not. Hopefully this answers your question! Have a good day!