I answer, and it take 5 seconds for a foreign voice to start speaking, the background noise are others speaking so an obvious call center of some type.

Possibly a spam type call, they were unclear as to what they wanted, and the connection was quite poor, so I'll hazard they were not inside Australia.

I hung up as I didn't really feel like trying to work out whet they were saying on a poor line. It has been a day and they have not called back, I guess it was not important.

I'll be blocking the number now.