Never in my life have I dealt with such a useless company, they should pay their customers to use their service - sending international goods is just a waste of time, what they estimate as 2-4 weeks you can guarantee will be 2-4 months (and that's crossing your fingers it will make it there).
Why New Zealand has such a useless postal baffles me, when comparing to a company like FedEx, NZ post is the equivalent of paying a mentally challenged child to deliver goods - I don't know if the couriers are distracted by cats on their way to deliver parcels or if they try to 'guess' where they parcels should be delivered.