I'm assuming this pertains to your ban appeal. When a server administrator denies an appeal due to "security reasons" it is because the reason for your ban is so old that it is no longer in the server's records. Because of this there's no way of knowing what you did to warrant a ban, it could have been something as small as grief or as large as using hacked clients or illegal mods. Since the latter is a perma-bannable offence, staff cannot risk unbanning someone who may have used it. Sorry for the inconvenience.
Aah yes, advertising is pretty serious. If you could find evidence of something specifically saying you were banned for advertising, that could help you out. Other than that, there's not a lot staff can do.
