If there is someone to answer the phone and give me an approval why isn't that person working the traffic instead?
Because that person is not rated to work that sector of airspace. In fact both those numbers give you the admin staff who assists the Ops Manager for the centre. She is not even a controller. She puts you on to the relevant supervisor for your enquiry.
The reason for the temp. restricted airspace is because there is only one controller to control Gold Coast approach airspace for the morning, and his breaks are notamed. This is due unavailablitity of staff.
Every sector of airspace requires a controller to have an endorsement to work that airspace. Just like pilots are required to hold endorsements for different aircraft.