ALesher04,
The Directory is based on the description, and it is lastname, firstname, but remember to have a space after the, as that is how it determines where the first name starts.
If the mailbox is associated with an extension/phone number, then you have to make that change under the Phones or the Hotdesk/Phantom section and not the mailbox itself.
If the mailbox is disassociated then you can do it right at the mailbox itself.
Thanks,
TE