[Scherzo]

Is it what you meant 'support for amxbans'?

Replace

                server_cmd("banid %d #%d kick",bantime,uid);

with

            if(is_plugin_loaded("amx_bans.amxx"))
                server_cmd("amx_ban #%d %d %L",uid,bantime, id,"WORD_ADVERT"); 
            else 
                server_cmd("banid %d #%d kick",bantime,uid);

Edit.
Now I know it`s not working, so don`t copy this.