This isn't the only problem I've heard of with TNT.

In the other case, TNT tried to deliver Snow Leopard to a suburb in Auckland.

Sadly for the recipient, the full address for the delivery stipulated another city. It seems that TNT stopped reading at the suburb, not realising that sometimes New Zealand cities have suburbs named the same.

Big dislike for NZ address formats especially how it is used in SW packages. Even NZ Address format makes a mess of OS X address book for all existing international addresses.
Translation of Australian addresses puts the State in Suburb (or leaves it blank), and the Aus Suburb in City.

You know you can specify a different format for each card in Address Book right? I've got different styles for UK, US, NZ etc

As it happens, I have been waiting for a UPS parcel to arrive, software from the U.S., and yes, how I presented my correct address, and how it became ' scrambled ' meant that it became undeliverable as far as their Auckland office was concerned !
Fortunately, a quick email has it sorted, but it shows your point is valid, but not sure how to avoid this happening again with consignments from the U.S.

And that's why we use Postcodes/

Well, yes, we have them, but they provide no certainty of delivery ! In fact, our regular postie uses the emergency numbers
( those little blue plates ) as the more definitive address code, and we now always include them as part of our address.

How can postcodes not guarantee delivery? That's why NZPost tells us to use them. Is this just competitors being jerks or what?

Since I have 1 piece of mail or courier item per fortnight get delivered to the incorrect street in the same suburb... I have little faith in NZ Post and Courier Post.
We have 3 streets in same suburb that are very similar. All start with same letter, two share the same prefix and two share the same suffix. Luckily we now recognise the surnames for each other and readdress or contact them. Fortunate an honest crowd especially had my case of wine left on the doorstep of another address.

DPID or smaller postcodes would help. Also seems that many new zealanders do not use postcodes nor know their own 'correct' postcode