Problem Solved. Went to their web-site and via the 'contact us' advised I would lodge an official complaint if these unwanted calls continued. A day (and two more calls) later, received this email:

Hi Ian.
Thank you for your email.
I apologise for any inconvenience caused.
We have removed your contact number from our automated dialler. You will not receive any further calls from Red Energy on 03 9435 xxxx.

Kind regards,
Jonathan McKibbin
Customer Solutions Consultant

T +131 806
F (03) 9425 0589
W www.redenergy.com.au

Like other comments, constant calls that just hang up. Rang this number back and got a recorded message, "Hi, you have been called by Red Energy...." at which stage I hung up. Caller identified! They are not my supplier and with these antics, never will be. Will now go to their web-site and see if I can leave a similar comment. Urge others to also do so.

I'm getting them too! I tried calling basck 4 times today 12/10/10 and it rang a few times then hung up...... What can we do about this it's really annoying!

I get calls from this number and there is never anyone there.

Hi,

I just googled the number and came across this site. Been getting calls on my home & mobile number and they always hang up before I answer. I've tried ringing it back but they hang up after a few rings. Strange!!

just got another on my mobile and they are flogging stuff for Red Energy. I have added
them to my phones contacts so I can just hang up from now on

I too am getting calls from this number on my mobile.  I haven;t had the chabce to answer it yet as it only rings a couple of times and then they hang up.

i just had the same problem - this has been going on nearly 2 years.