Caller: Unconfirmed scammer

They’ve been calling me at ridiculous hours all week. I finally answered and just listenened in, but they hung up.

If it was a professional business I’m sure they would of said “hello” or listed their name.
I called back a couple times and a voicemail recording of “There’s no operators available” played and then they discontinued the call.

I called back number (02) 4067 5002 reached voice mail but did not say for what company.