Dear tine1803,
First, I want to say I'm very sorry to hear this news. It does seem to me that the immigration officer is making his own assumptions about your case, rather than relying on immigration guidelines. I faced the same situation (although about work-related issues, rather than relationship-related). Further, they have made widespread cultural assumptions about how comfortable a person should be talking about very personal issues, such as religion. It sounds terrible. Even I know about daal vs. curry, and I've never even been to South Asia.
It also sounds "very INZ". There have been many complaints about inappropriate approaches to cultural differences, including with Maori applicants, so I just want you to know you're not alone, and there are many people who struggle with this too. :l
I have begun an Ombudsman complaint. The office said it would take them about 3 months to consider the complaint. So, depending on your timeline, it may not be too long. IPT (immigration tribunal) takes 6 months.
In my experience, INZ have not cared at all about their violations of immigration regulations -- and they even shared illegal activity with me in writing. It's also important to understand that the complaints process DOES NOT CONSIDER MERIT-BASED COMPLAINTS. Only PROCESS-based failures are considered. So, unless your decision was made based on a missed process (like, they were supposed to interview you as part of the second step but they interviewed you as part of the fifth step), you won't get any help. There is NO help for them making the wrong decision based on the evidence, being culturally inappropriate, misinterpreting instructions, or even making a decision based on incorrect facts and inaccurate info. My complaint resulted in apologies for a dozen errors made on my application -- and that's it. Also note that the complaints process allows 5 weeks for a response.
From my and all my friends' experiences, living together for 12 months is KEY. I have friends who are white, Christian and from Anglo countries who were married and couldn't get a partnership visa because they hadn't lived together for 12 months (because their religion prohibits living together before marriage.) He came over on a student visa; she had to get a Silver Fern visa.
Here are some thoughts:
1) Get a letter from the father if at all possible.
2)
Is a tourist visa a possibility for your partner to stay? If so, you can apply for a tourist visa (3-6 months) with the explicit purpose of visiting someone in New Zealand. This will allow the extra time you need to live together and prove 12 months. This may be the easiest way to solve your problem.
3) Write to CO directly and say you feel the information was interpreted without considering the culture and your approach to religion. Ask for the CO to reconsider. When the CO declines (which is the most likely scenario), you can move up the chain in INZ if you wish and initiate a complaint. I wouldn't count on any help via this route, but you may have to do it anyhow.
4) Initiate Ombudsman complaint. The more the legal system is aware of these issues, the more there may be a larger inquiry into what is happening. An inquiry was initiated in 2008/2009 because of "target based" immigration policies (going for immigration numbers rather than evaluating individual applications) and clearly that has happened again. Both political parties talk about immigration policies in terms of numbers.
This isn't about you -- it's about reducing immigration. Note that INZ will only talk to you via Complaints if you are not talking to anyone else (Ombudsman, IPT). And you have to choose between Ombudsman and IPT -- you can't do both. But, if you start Ombudsman complaint, it will take a few weeks before they look at your case. In that time, you can communicate with CO / INZ. Once Ombudsman starts to consider your complaint, you can decide how to move forward with either INZ or Ombudsman (because you'll have to choose).
And, maybe you will have a tourist visa -- in which case your problems could be solved. Pick the easiest route for resolution, even if you are "right" that your application was inappropriately decided. In the end, it's your relationship that matters.
Good luck
...Gaida