[.:Kaos:.]

Actually Josh, Lorenc_ is right. Ban(playerid); is a function WITH SA-MP, but doesn't ban in the userfile. The function bans them on a IP basis. So to unban them, you need their IP, and '/rcon unbanip IP'. Although you can make a Ban function in your script, via enum or whatever it may be that you use. And Josh if you are to self-centered to believe me, just read this: https://sampwiki.blast.hk/wiki/Ban