I called the number (03) 8582 0092 but I only got an automated system saying that they are unable to take calls right now and for me to call back later. The call disconnected right away.

This number rang my mobile and went to voice message. When I retrieved it, there was on message, just silence.

This number rang my mobile while I was out. When I rang it, I got a Telstra message to say that "this number is not in service. Please check the number and dial again".
Obviously someone has figured out how to mask the real number they are calling from.