The whole thing looks like he does not have acces to the Admin Server Query. He did this change whith his own query login.

polimarek0 do you own this whole server? In that case you have acces to the loginname serveradmin?

Please send this command into putty or telnet. (This works with the login "serveradmin" only!!)
Code:
login serveradmin yourpassword
use port=9987
servergroupaddperm sgid=6  permsid=i_needed_modify_power_client_needed_whisper_power  permvalue=75  permnegated=0  permskip=0