I called back number (07) 3088 5882 reached IVR of telstra.

Called me twice today, once before mid day and once just before 20 past two. didn't answer both times but wanna know who it is.

I answered and they just keep hanging up on me.

It's Telstra business services in this number.

someone called me and don't know who it is.

What a great idea!! Insult the people you are asking for help.

Try answering the phone call and ask them

This numbers been ringing my mobile and my wife's mobile for a few weeks and we don't know who's number it is and they don't leave messages in voicemails...the reverse search shows it's not even listed.. What the f*** ..!!! How does that work..???? How do you have a number and not have it listed..??? Unless you're some prick of a telemarketer firm..?????