[Polomikey]

Okay this is what you do.
Open back up the server
Login on rcon
do /rcon players
Then the user that is spamming
If you see his ip and his playerid do
/rcon ban (playerid) CONSOLE
or /rcon banip (IP).
If that don't work
I'll send you a /banip command to ban them
Give me a rep+ if i helped you.
PM me the server ip.