I called back number (03) 8814 2028 was put on hold music but no one answered the call.

I picked up the call. then hang up.

Caller: Some Australian Government Agency

(03) 8814 2028 called, heard call centre noise I said "you going to answer me", a guys voice said "oh sorry we're having computer issues, went on to ask if I owned my own home etc..." i told him to remove my number off the call list his response was "Sorry I can't do that we're allowed to call you", my reply "really ok no problem I'll block you then" he then hung up.

Multiple calls regularly. On calling back, onhold music. Probably marketing.

answered and could hear lots of people talking like in a large call centre, then they hung up