I don't know any details of that contrib, other than the name of the server-manager panel script. So let's use that to find the name
of the contrib rpm:
rpm -qf /etc/e-smith/web/functions/advuseraccounts
and now let's use that information to remove the contrib rpm.
rpm -e $(rpm -qf /etc/e-smith/web/functions/advuseraccounts)
Now you need to use the 'reconfigure' option of the admin console or the server manager to reconfigure and reboot the system (which will remove the link to the advuseraccounts panel from the server-manager).
Before you do any of that, you should report whatever is wrong with the advuseraccounts panel via the bug tracker ("not working" is not sufficient detail), so that someone can fix it. Go to
http://bugs.contribs.org/ to report the problem.