Well last time I checked you cant type !setlevel Chomps 5....
You will need to use RCON. In server.cfg there is something called set rconPassword.
So it should be like this:
set rconPassword (some crap)
Edit (some crap) to a password. (dont tell anyone the pass). Now go onto ur server and type /rcon (the password) !setlevel Chomps 5