Same as previously stated. Sounded like it (unfortunately) recorded voice to perhaps use against any voice activated confirmations that have been set up. Fortunately I don't have anything like this, but watch this number...

I answered by just saying hello and the voice I heard back was my own saying hello, then it cut out.

They have called continuously 4-5 times a day for over a week. When I called back I get the number cannot be connected message
Very annoying

Caller: Unknown

Also called me on (02) 7259 5777 and (02) 7252 5072, I didn’t answer deleted 101 message without listening and blocked the numbers

Caller: (02) 7252 4702

Keeps ringing daily, no message left, when you return the call it says number disconnected

Caller: spam

picked up & no one on the line. It sounded like it was connecting to someone, so seems like a classic spam set up

Caller: (02) 7252 4702

Called for several days, when I picked up (but didn't speak) it was just silence.

Same as previous, heard my own voice then cuts off