Hello, so about a year or so ago I was banned permanently from playing Halo: Reach online. My rank was Noble and I’m still trying to find a way to get it unbanned, all I did was use a software to change my Service Tag, which I know it violates the Guidelines, but to permanently ban an account for something harmless like that? It makes no sense. It was simply a smiley face like this 
Anything that can be done?
Sorry OP, but these bans do not get reversed. You can reach out to Xbox Live Enforcement but you knowingly broke the rules regarding moding. Doesn’t matter if you feel it’s harmless, at the end of the day you still did it.