It belongs to Alinta Energy marketing team.

Five times in two days

Caller: Unknown

Rang 5-6 times. Pause. Another ring tone then recorded message asking to leave a message or * for another option.

once I answered the call from my mobile the person or computer hung up immediately?
I rang back and it went to message saying "leave a message or press star for an operator",I pressed star and it asked me to leave a message?
what is this about? it is not the first time I have had these types of calls. Personally I think its a computerised call

electricity

I called back number (02) 9002 3200 rang 5 times then goes to busy tone.