I didn't realize there were cell phone / mobile phones for seniors, but I heard about the Jitterbug mentioned.
There's a similar locally sold cellphone from Doro 6520, review
For these below, I believe the only source for the following is outside NZ: Amazon or Ebay
1) Jitterbug Smart
2) BLU Tank 3
3) Snapfon Ez One
4) Alcatel A383G