Same. call from overseas to Perth WA. My colleague picked up the phone, some from of marketing but I wonder if international charge applies by picking up the phone.

Caller: Scammer

If you don't know what to do, here's a bit of information.
If you see any phone number from an overseas country, chances are 100% it is a scam.
Any Australian phone number you don't know, let the call go to the message bank (if you have one).
Same with any SMS or MMS. Do not answer the call or open the SMS or MMS, just block and delete.

By answering the call and/or opening the SMS or MMS, you are letting the scammers know that your phone number/s are viable and they will sell your number to other scammers.
NEVER CLICK ON ANY LINKS sent to you via SMS, MMS or email from an unknown source. Scammers can make a legitimate website look exactly like the real thing, but they set them up to take all your money and personal identification

SCAM WATCH Australia has some good information on what to watchout for and what to do,

Don't know who call. Google suggested the area code is from Sri Lanka however we are in Perth Western Australia.