Seems like a popular deal in the past. Found this while trying to use the $20 credit (Nest Hub Max fiasco) for something worthwhile to buy.
As much as I don't like to give them any extra $$ for unnecessary spend, this proved useful.
Check ur local store for pickup or pay $5 postage.
This is a was a better deal.
Hopefully it will be available again
https://www.ozbargain.com.au/node/534045