I called back number (08) 9467 4406 rang once then gets disconnected automatically.

Hard to do when they call your work phone and so you don't know every number :(

Same response as everyone else.

Caller: Unknown

Same as the other comments, if you answer there's just silence. I tried calling back, because usually you find there is no phone at that number at all, they're just using it to look like a legit caller.
They're scammers alright but I'm not sure exactly what they're up to. Calls like this, they don't try and sell you something, I think they're just trying testing for what numbers will answer the call, which ones aren't worth bothering with and so on. I know they sell lists of phone contacts and similar, maybe someone's making up new lists to sell to the ppl who actually call you, later on.
Either way it's not good. It's like, almost ANY incomnig call from a number you don't recognise, is suspect. It's pointless blocking their number when they call, as they'll be using different made-up numbers every time. I think the thing to do might be a white-list, where only people already on the list can call. It's a bit drastic but if you're being plagued by these maggots, it might help

Caller: (08) 9467 4406

Reported and insisted to telstra to do something about this internet call piped thru our phone lines. Aldo sent it to our local MP. Then blocked number

Caller: Scammer

Don't bother answering, block the number and don't call back

Caller: Yet another solar panel scheme

To their credit the guy was very chipper and agreed to remove my number when i asked.

As above, Answered and then silence before hang up. Time to block it.

no message left by this number, when caled back it rang continuously.

called, never answered when I rang bck

Took ten seconds to talk, hung up and blocked

Caller: Solar Panel People

Solar Panel

Just received a call from this number and got silence

Caller: scammer

missed a call from this number. when i called back it dialed an international ring tone.