PromNZ: Rather than a credit card, get one of those Visa debit gift cards. Does the same as a normal CC enabling you to buy stuff online. NZPost sell them. Details are here.
So far it's taken 3 weeks for my Action Replay unit and it still hasn't turned up (holiday weekend probably doesn't help). You could probably pick up a debit card and buy from the Auckland guy quicker tbh. You don't need a CC to be authenticated user, you can do it with internet banking.
This may be off topic, there is a new one, I don't think Prezzy can be used on line as such as no names and you can't top up, but this one you can same outfit, NZ Post.