NZ is playing fast and loose with this area and it's very akin to those "x months interest free" deals you see often (excludes Microsoft products, the latest Apple product, other product we arbitrarily decided (probably because we don't make much on it but thought we'd entice you in anyway) and other product you want)

BUT at least they have it on the fine print on the page where they make the advertisement. NZ doesn't. There bury this information multiple layers deep within there website and most people will not deliberately search out to see if they will not get something.

I can 100% guarantee you that everyone would be (rightly so) calling the OP an idiot if the page looked like the following, but NZ wouldn't do that because then their profits would plunge because the offer is substantially less appealing. The explanation from NZ, as it is, is very halfassed and you could almost go so far as to say deliberately misleading.