Hi Jinx,
As stated previously in this thread, all bans can be appealed (by the banned person), by simply using our contact form which is linked at the bottom of every page of our site.
We occasionally give an "expiration" to ban, but in most cases we keep it simple and make bans "indefinite", meaning until or unless a ban appeal is accepted.
We've actually accepted many ban appeals (I mean unbanned many people), usually because the person is sorry and we think they're sincere and won't give us more problem. Sorry to say, we often regret unbanning people because often it just results in even more trouble for us and then a permanent ban.
Also occasionally there has been some misunderstanding and after it's explained in the ban appeal we unban the person.