Got a call from this number 3 times within one hour.

i answered the phone and it was silent i kept saying hello but no answer and then they hung up.
I could hear them doing something in the background.

Its 'National Hearing Care' - just called them after they called and simply hung up, i have now added their number to my PBX's 'block list'

answered phone and they just hung up.  I believe they have phone number generator like most of these places and just ring which ever number comes up.  We are a business.

I received a call from them it rang about 4 ring so i didn't get enough time to answer

I answered and they immediately hung up. Call memory showed (07) 3018 1190.

Received call from this number today - I answered with my name and they said sorry wrong number - and hung up. Wondering what they are collecting - all they got was my name (I wonder what other information they already had.) I will probably receive a phone call in the future saying hey xxxx we met the other day did you want to give the King of Albania money so he can transfer his gold to your account.

Hung up when answering machine came on

They called, I picked up, and they hung up as soon as I said 'Hello'.