It's actually a pretty simple concept, follow the Network Rules we have in place, or deal with the punishment that's given when you break those rules. The reason you cannot appeal temporary mutes is because they're usually pretty short, and either way it is supposed to serve as a warning so you don't do the same thing again. You CAN appeal once you've been Permanently Muted for 10+ Mutes, and you may or may not be granted a reduced punishment, dependent on why/when you were muted and your appeal.
Locking Thread.