Just had some weird experiences with OneNZ this evening, figured worth sharing.

My employer is a customer of OneNZs, and we get access to the Enterprise Offers with a small discount on our personal plan as a result.
https://one.nz/enterprise-offers/
The other day I submitted my personal details on that form to apply the discount to my existing OneNZ account.

Today I got a call from 0800 800 120 - saying they were from OneNZ and to discuss the offer I'd requested.
I confirmed my name, and then they said they were sending me a code to my mobile and I needed to read it out to them.
I'd asked them why, as I'd given all my account information on the form already and had not requested additional services - it's an existing account and no changes are being made other than applying a discount. I also said I wasn't comfortable providing a code to them since I too can't be sure it's OneNZ calling me (though 99% sure it was, due to the earlier form filling). They said it was needed for my account security - and to reassure me they could email me separately to verify that it's OneNZ.
I asked if I could call them or their team back on the main line, and they said no. So I told them I'm not continuing the call and hungup.

Later I started a chat in the OneNZ app:

• Chat 1: Said there would be a 1hr wait and I'd get a text when a rep was ready. I got a text reminder sure enough, only to open the chat and see they'd disconnected due to no response. Great.
• Chat 2: Billing rep couldnt help, said Sales could help with that and transferred me.
• Chat 3: Sales rep verified my full name and query. Then said they can't help and I need to speak to the backend team again. 
  They said - submit the form again and wait for the call, when they call you please cooperate with the verification process

It just seems to go against all advice which is not sharing verification codes with people - and looking at OneNZs own website they say not to "Give out any information about yourself – even if the person calling says they are from your bank or other business that you use. (One NZ will never ask you for your personal passwords, banking pin numbers or any personal information. We would only ask security ID questions that’s in our records to identify you)"
https://one.nz/help/frauds-scams-and-safety/