i called the number back and it went to voice mail without saying who or company. funny thing was the number the voice message said was unavailable was a sydney 02 number not the dialed 03 melbourne number.

I returned a call from (03) 9964 6802 but the voicemail didn't mention the company name

This number has called me a number of times but never leaves messages.
Called the number - message the number at that extension: (02) 8066 6989 is unavailable.

This number called me two days ago and just now. They didn't leave a message so I am blocking. I think that if it is a 'real call', they will leave a message.

I called back number (03) 9964 6802 reached voice mail but did not say for what company.