Just a warning TPG charged me $11.00 to port my phone number to a new provider.
I did not realise that was a thing. They also pay themselves from your debit a week before payment is due. Ripped me off last month by taking the funds before I could port out!
It's on their terms and I feel we'll known on OzBargain :)
They aren't doing anything dodgy charging it, just the only telco now doing it, that I am aware of. There used to be others (years ago).
So no, they haven't "ripped" you off, everything is above board.