Sorry you had a poor experience with the cabin crew. Generally I find NZ's to be very good but occasionally you might get a poor one.

Echo the above suggestion. I did something similar once when flying with QF. Had a FA who snapped at me a couple of times for very minor requests (similar to yours). As I disembarked I asked her her name, and she asked why. I replied that I wanted to add it to a flight feedback email. She very sheepishly told me.

A few days later I flew the same route and had her again. She had totally changed and went out of her way to be lovely to me. Never did send the email!