Australia Reverse Phone Lookup

have been called twice from an indian accented person claiming they are from windows sevice centre, he says that my computer has been hacked and they want my details to "fix the issues". i asked the man where he was calling from, he replied he was using the phone internet, calling from the Sydney windows service centre. i again asked him for his phone number and email address, he said he would give the details to me after he "fixed the problems on my computer". he started to get a little forceful so i again asked him for his details, this time with a little anger. he promptly hung up. 2 hours later the same damn phone call asking the same questions. be very careful about giving out this information. Who do i report these activitys to?