Why am i banned from the forum?


You are not banned. It sounds like an actual spammer was banned by IP (as that is how one bans spammers), and you are using the spammer's IP.  If you were banned, you would not be able to post at all. No one would intentionally ban a user by only blocking their IP and not their username. While you were warned in the past, that  has nothing to do with what is happening now. You are connecting two unrelated events.