Spam call....... silent then hangs up (several times tonight)

Just had a call on a terrible line from John Smith with a strong Asian accent. Said he was from NBN then started asking if I had noticed Internet issues. Could see where it was headed so hung up but he tried to call straight back

Same here someone did say hello but hung up called back constantly engaged.

Nobody talks when you answer the phone???????

Hung up when i said "we are on the do not call register, why are you calling?"

The scammers are getting more detailed ... when I hung up on this one the first time [after he claimed his name was Ryan and he was calling from Newtown in Sydney, but had a strong Indian accent], he called back!! Not once, but twice! I answered these, and he gave me a string of letters/numbers to write down, saying these were my licence from Windows, my product number and my computer ID number. I played along this far, but when he instructed me to get up the command prompt and go to 'computer management', I just said NO and hung up. The fourth time he called I didn't answser the phone.