Ok, the fastest solution to this is to edit:
helpdesk.php
Search for:
print_no_permission();
Replace with:
// print_no_permission();
Do that to the entire document, save it, upload it then set your permissions in user group settings for your admin group to have "yes" to everything, set your departments then undo your changes to the file, removing the // and re-uploading it.
This should get you up and going, I added my admins before I locked everyone else out with the perms.
good luck