This is a deal that has been running for a while and recently got posted again on OzBargain. It is now available to both NZ and Australian residents.
I signed up before and received a Chocolate Chip Crisp Bar and a Milk Chocolate Mint Crisp Bar which both tasted pretty good. You may receive something different.
You don't need to register and activate your account, which is a plus. So use any email address, but obviously a real delivery address. There's no need to enter DOB & height, but if you must, note there's an error with the DOB field. You need to enter DD MM YYYY.