It's a common problem in the older suburbs.
It is because a lot of the bigger blocks are being cut up for duplex or triplex or apartment housing.
Years ago they would have run a bigger main bus to cater for the increased lines required, knowing that even if they didn't have customers for all at the time, it was always an increasing market so the lines would eventually be used..
That no longer applies.
It's old technology and it's on the way out.
So,.. what they do is, when someone cancels their service, they use the line on the main feed bus to connect up someone else in the area.
They are not going to waste money putting in any more copper service lines because it's about to be made obsolete,.. one day,.. soon,.. maybe,.. later,..but they think soon.
If you request a service you will go in the que and wait for someone else to cancel their service so you can have their line.
If there's a hundred people in the Q before you then you have to wait for 101 people to cancel.
It may take some time.
Not much you can do about it except claim you are on deaths doorstep and need it for medical emergencies, or are an important diplomat or something and the line is required urgently in the national interest. They may require proof.

Or make friends with someone high up in telstra.