According to AVG there is a mobile phone scam circulating in Australia.
Have you had any missed calls lately from a phone number that you do not recognise? The natural thing for many to satisfy curiosity is to call the number back. Don’t.
It is possible that this is a scam call designed to suck your phone credit. The call is redirected to a prefix 190 number which are premium calls. This happens without your consent or knowledge. Immediately, your account is billed at premium rates. Even just dialling the number can attract a steep fee.
For more information read the full article from AVG.