Buy TNZ microSIM + top-up at the Warehouse. Enter SIM. No service is displayed. Go to settings and manually select TelecomNZ after it finds all 3 networks Still no service. Go to SIM applications and see a roaming menu app. Select manual, asks for a code which seems to be the PUK, so do that and still no service.
To test coverage insert a Skinny microSIM (hopeless as the url in the SIM guide takes you to a 404 page) and Telecom NZ comes up straight away with full signal strength.
Is this a non-registered SIM for the iPad? Anyway to activate this without a call to the contact centre and a wait of 20 minutes to get it sorted?