Probable female Indian hoax caller, allegedly from Optus

The lady who called had an Asian-sounding accent and said she was calling from Australian Mobile. I just told her politely that I was happy with my mobile service and that I wasn't interested, then hung up.

Caller: Scammers

Was from Indian person claiming that I am getting a refund from his company, wants all information about my details and me wants to download a assist program so he can get into my system then tries to steal all my money calls himself Neil Johnson or Johnstone

I suspect that this number was being used by scammer pretending to be from the ATO (who usually seems letters if you owe them tax, don't they? )