If summons have not been served on husband for last 3 years your remedy is to make application for substituted service ie paper publication in 2 local newspapers in city in New Zealand wherein he is currently reading 

2) complaint through embassy would not serve any purpose 

No complaint to embassy will be effective.

For divorce petition you may proceed to obtain exparte divorce if he's not traceable despite sending summons to his last known address by adopting the procedures for substituted service of summons.

You can get exparte decision in DV case also and follow the procedures to attach his property to execute the DV maintenance or compensation award.

You can discuss with your advocate and proceed accordingly 

- You can move an application before the Court , to summon your husband through the Embassy

- Court has its power to call your husband from Newzealand, under the following provisions,i.e. 

The Ministry of External Affarirs, has, on the basis of Look Out Circulars/Non-Bailable Warrants/Summons/Court Notices, suspended passports under Section 10A of the Passports Act, 1967 and impounded/revoked under Section 10(3) of the Passports Act, 1967, of Non Resident Indians (NRI) husbands.

• You can lodge a complaint against your NRI husband through the Indian High Commission in New Zealand for assistance/advice, to file a complaint with the local police about harassment, abuse, violence, etc. The Indian High Commission can also assist in providing contact details of local NGOs, approach the local police, contact your family/friends, etc. who could help you.
• You can also try to contact the local police in your area and inform them about the situation. They can guide you on the legal steps to take within your jurisdiction.
• According to the FAQs on the India Post website, you can also send the court summons by registered post with acknowledgement due (RPAD) to your husband’s address in New Zealand. The RPAD service provides proof of delivery and a copy of the signature of the recipient. You can track the status of your RPAD online through the website.
• According to the website of the High Commission of India in Wellington, you can contact them through the following address, phone number or email:

High Commission of India Level 9, 180 Molesworth Street Thorndon Wellington 6011 New Zealand Phone: +[deleted] Email: [deleted]

• You can also contact the Consulate General of India in Auckland through the following address, phone number or email:

Consulate General of India Level 2, 121 Beach Road Auckland CBD Auckland 1010 New Zealand Phone: +[deleted] Email: [deleted]

• You can write a formal complaint letter to the Embassy/Consulate stating your name, address, contact details, passport number, marriage details, husband’s name, address and contact details, brief description of your problem, copies of relevant documents such as marriage certificate, divorce petition, domestic violence case, court summons, etc. and request for their intervention and assistance. You can send the complaint letter by post or email to the Embassy/Consulate.

File FIR. Warrant will issue and impound of passport. 

Yes you can file a written complaint against him in the embassy and MEA if required 

Dear Client

Contact the Indian Embassy or High Commission in New Zealand:

You should contact the Indian Embassy or High Commission in New Zealand to seek their assistance in serving the summons and other legal documents to your husband.
You can find the contact information for the Indian Embassy or High Commission in New Zealand on their official website.
Legal Assistance:

Consult with an experienced family lawyer in India who specializes in international family law matters.
Your lawyer can guide you through the process of seeking assistance from the Indian authorities in New Zealand and advise you on the specific steps to take.
Indian Ministry of External Affairs (MEA):

You may also contact the Ministry of External Affairs (MEA) in India, particularly its Consular, Passport, and Visa Division, which deals with issues related to Indian citizens abroad.
The MEA may be able to facilitate communication with the Indian mission in New Zealand.
Legal Remedy in India:

Continue with your divorce petition and domestic violence case in India, and keep the court informed of your efforts to serve the summons.
Your lawyer can request the court's permission to serve the summons through alternative means, such as by publication in a newspaper, if traditional methods fail.
Keep Records:

Maintain a record of all attempts to contact your husband and serve court documents.
Document instances where you tried to reach out to him through email, WhatsApp, or any other means.
Consular Services:

The Indian mission in New Zealand may offer consular services that can assist in serving documents or facilitating communication with your husband.
Online Complaint:

Some Indian embassies and consulates provide online complaint submission forms or email addresses where you can contact them.
Check the official website of the Indian Embassy in New Zealand for information on how to submit a complaint online or through email.

Court summons could be arranged to be served on the husband in New Zealand through our High Commission there if his address is known. As it is only a matrimonial matter, the High Commission may not intervene.