Caller: unsolicited caller

Even Google Telstra and Optus have no record of this number. It LOOKS like a mobile number but its most likely (imho) to be a V.O.I.P. generated number from a scammer.
With no known identity from trusted sources or in my contacts list, I deleted the message & blocked the number.
The voice message telling me I owed money for a service & to pay now or get penalties.

I suggest if you get this number on your phone that you block the number delete it & report that number to scamwatch or Telstra security services Australia.
Anyone that knows a mobile number to be allocated by telcos starts with 04 but then the next digits relate to your areas (postcode) business or standard person use.