Managed to get 5x$100 at the 2nd store I went to this morning. Last ones on the shelf.
First store had none. When told about the promo staff said they sell out quickly and that people hide them. Of course this would be no secret this is happening when the shelf stackers find random gift cards behind tins of pet food. 
Staff at both stores didn’t even know the promo was on and couldn’t see any advertising of it. Brisbane CBD.
EDIT: will be looking for another 10x$100 cards throughout the week. Different stores.
