It's used by Internet Service Provider iiNet.

I got a call from this number (iinet) at 6am and 9pm which i think is a bit much. and its partly why i am changing company if you bill is short by 5 cents they will cut off everything including your home phone so you cant call them back.

i got a call from this number after telling iinet I wanted out of my nbn contract - they disconnected my netphone before the bill was due, they said the usage was to high.
I had one relative dead and two in hospital over the last 2 months, bill always paid on time, no real reason for it. Glad to pay a $400 disconnection fee to get away from them.
Wankers.

I got two calls at 5am from this number.

I say that's 100% too many indigenous

One ring and they hang up

I had threatened iinet with a TIO complaint if my issue remained un-resolved. They then advised me that they were going to investigate further and they would call me back.

So I suppose that may be the "call-back" now documented on their systems? Anyone else have a similar issue/ theory?

Either way, TIO it is...