Caller: Said they were optus for an overdue bill

the woman i spoke to (when she eventually spoke after a lengthy gap between my hello and her speaking) said they were Optus for an overdue bill.
tried pushing me quite hard for an immediate payment, then and there. i refused as i process all my payments myself, not over the phone to some stranger.

Caller: Said they were from Optus

Either a scam or unsolicited sales call. I hung up as I have no account with Optus or reason to talk to them.

Scam. Using bots to flood my phone with calls nonstop for a full ten minutes a day before.

I called back number (03) 9093 0629 reached IVR for a company called The Probe Group.

Just wondering who called me

Spam number. say they're optus chasing an overdue bill. Number has no connection to Optus.