There is 30% cashback at Myer when you order through the Cheddar app. This is capped at $100 and cannot be used for Chanel or Dior products. You cannot use Myer Gift Cards to pay and need to order through the Chadder app (and not Myer App).
You may be also able to get $20 signup bonus when you download Cheddar from https://www.getcheddar.com.au. I am not sure if the existing $50 signup bonus still works using https://getcheddar.app.link/web50sup. More info OzBargain