I saw this on Manners St, Wellington where the NZ Post + Kiwibank shop has recently changed into a full Kiwibank branch
This apparently happened before as earlier as October 2017 in Rotorua and December 2017 in New Plymouth.
In Wellington CBD if you want a full NZ Post shop you have Lambton Quay, Featherston St. Other services are available in pharmacies, supermarkets.