Well, you have to take under consideration what R3D said. Most networks do not allow banned people to talk in the channel (some still allow if you're opped).
So you need to check and see if that network you're on allows that or not. Another way out is sending that !unban command in a Private Message to the bot, IF it accepts those commands in pvt.
If it does, then paste that into your remotes:
on *:BAN:#: {
if ($banmask iswm $address($me,5)) {
msg <BOT's NICKNAME> !unban $me
}
}
You must change it to the bots nick, and perhaps change the command as well... there are some bots that respond to different commands if they are sent via Pvt.
Good luck!
Zyzzy