Whilst New Zealand is a comparatively small market, it's one in which Samsung generally does very well. The Note 7 was no exception and as with other countries those who still have the handset are somewhat reluctant to give them up.
I'm guessing their view is that the Note 7 is so good it's worth the risk of a few burns.
Not a view the NZ telecoms providers share and through their forum this group has announced an agreement to cut the Note 7 off from all Kiwi networks in November 18. Hopefully this will encourage the remaining stragglers - a figure put in the hundreds, not thousands - to finally replace their phone with something less likely to combust.