Same here constant annoying calls with no answer.
Reported the number to "report @ submit.spam.acma.gov.au"
Hope this puts an end to their calls

Calls from this number repeatedly...I take name & company details then tell them we are on the DNC Register....they hangup in my ear then!!

Didn't disclose anything to him but I was in the mood for some fun - spent about 15-20 minutes trying to get information from the cold caller. Max from "Australia Assessment Office" who when I asked for verification of company by giving me address and phone gave me an address of 51 CBD Downtown Melbourne (like to know where that is) then after me pushing the issue with him verifying legitamisy of the company he put me onto his supervisor Alex who told me the company was "The Solar Company" and gave me an address of 32 Melbourne CBD (again, where is that?). I queried how they got my information and was informed that a government department provided my name and phone number. Alex ended up hanging up on me! I challenged both of them whether it was a marketing call to which they both replied "no" but then were wanting to make an appointment to sell me something - if that's not marketing I don't know what is.

I get drop out calls from this number also..no one answers

just dropped out when I didn't answer at 1.53 pm

Probably an automatic dialer that logs when a phone is answered and wof course what time of day someone is home.
e.g. Auto Dialer Software - Boost Sales Calls by 50% or More‎

more solar panel scum, Said his supervisor who had authorized the call was Bend Over!

Same as above missed calls or when you do answer nobody speaks. When you phone back no one answers the phone.

Say they are from Sustainability Assessment Office and in the area to assess your suitability for solar power. No trace when Googled.

Keep having miss calls from that numbe, got them last night around 7pm
Told them my number was on the do not calm register and hung up
Guess who called again today already 3 time.
I get them tonight and I will tell them I will call the police if they call again. Usually works a treat.
It was an Indian female on the phone.

2 calls. Nothing said, returned call but got " congested lines" message.

Keep getting calls from this number, we are even on the do not call register and our number is private.
I thought that I will ring them back and hassle them but they never answer their phone.

this call while I was out ?

While out, received a ph call from (03) 8592 6407 ?