Same thing happens too me, miss lots of calls from the same prefix 038664...., when i answer no one there, cant call back??? weird

me too!

Started getting calls from various nos. this week.  Rang Telstra and they said it is a marketing firm and the calls are computer generated.  If an operator isn't available to speak to you when you answer, the call hangs up. Ring the DO NOT CALL REGISTER 1300 792 958....it takes about 30 days to come in to effect, but worth a try.

Me too.  but it happens lots and it started about six months ago.

That number just called me again and I answered it about half way through the first ring (almost instantly). It was TELSTRA asking me if I was happy with my phone plans etc...

this number calls me and i cant call them back. i would like to know who it it.