I had a call from this number and was about to ignore it. I am so glad I didn't. It is Origin Abolishments which I have been waiting for (electricity) so that we can demolish and rebuild our house. I see the other comments are from some years ago. Perhaps the number has been re-allocated.

I had a call from this number; it was from Ambulance Victoria re membership.

This number is Ambulance Victoria just reminding me my membership has expired.

I had numerous calls from Telstra, but from other numbers. THey called several times a day for weeks until I answered it. THey asked me for my security detailsso they could tak about my plan with me - I refused to give them. Why would I? They called me - they could have been anyone! TOld them if I wanted their help I would ring. BUT my dad has encountered this too. They apparenty have a box on their screen that is a 'do not contact for marketing' box - you can ask them to tick this box. They have to if you ask them to.
Anyway I just had a call from (03) 8612 7700 and googled it - here we go again!
I'm going to answer it next time and ask them to tick the box!

Thanks Jackie for the number to block unwelcome calls. I also got a call from the number. no messages left on my voicemail. I am just going to block the number because it all sounds dodgy to me.

i've received calls from this number (03) 8612 7700 2 times every day in the morning.  When i answered, no one speak so once i hung up and redialled the number.  The call got answer by an automated person saying that i've called UCMS, they recently called me on behalf of Ambulance Service Victoria regarding my membership (which i dont have any) ?? and if i wish to discuss in details i should call 1300 366 141.  
How do i stop these calls??? Very annoying

I have Several calls from this number too.They dont leave messages.V.V. Annoying

I got a call just then from them, they said they were from the Ambulance and asked to confirm my ambulance membership details or something, I said they had the wrong number (because they were calling in regards to the previous owner of my mobile number) and they apologized and hung up.

yeh i recieved a call from this number (03) 8612 7700 as well it apparently was a telstra survey asking me questions so i could get the "best" out of my prepaid service. so i dunno WTF is with. mayb its legit or mayb its jus some dogde company conducting surveys.