am from australia and i have been getting this call too.
i never answer it because it feel it is a dodgy call/caller.
i tried to ring it back - with my caller ID hidden - and a recorded message came up - "number is unavailable - please check the number before calling again." so basically - it's one of those scams.
the only thing i can think of is - this could be as a result of me responding to the SUNRISE cash cow which i
actually responded to last week...other than that - i dont usually get these calls....
Its from a hotel and resort company wanting you to get $50 voucher and then $1000 in travel resort vouchers if you attend one of their seminars to try and get you to invest in one of their timeshare resorts. Not really a scam but a waste of time most likely as those $1000 vouchers are rarely easy to use or are not as good as they sound.