I have blocked this caller for similar reasons as per previous recipients

Caller: (02) 4047 9271

I blocked my number and called back, robot voice saying, "please enter your pin number" ( as if ) ;-)
so i left it on speaker for about 2 times and it says, "verification failed".
The number comes up in Newcastle area.

yep same as reported, Newcastle. Delay... blocked

Called by this number. A voicemail message was left. When I checked the voicemail, it sounded like a whole lot of voices talking together with no understandable message actually left.

I rang once and got disconnected