This number is a scam. The guy tried to make a big profit from changing the ticket. He said that only the more expensive fares were available and I’d have to pay $800 more. I said no thanks and he said he could reduce it $700 if I pay by visa. I said no thanks and he said would you like to speak to my manager. I checked online, it cost me $180.

Caller: This is a Quantas helpline but ...

They don't announce themselves when they answer. They then told me I couldn't book a flight online because it wasn't available - when it showed up as available, and that it was 'because the website wasn't updated'.
They tried to sell me a flight that cost $800 more.
I then reloaded the page, and tried again. I booked the flight.
I said I would book through a travel agent to see what the response would be - he hung up.
Could be legitimate bad customer service from Quantas or a scam number?!