For A List of  Fiat  Ducato  Service Centres  in New Zealand 

These are the only service  dealers  to use for under warranty  Fiat Ducato  vehicles
   Servicing is required  every 12 months or 20,000km  - ( which ever occurs  first  ) 

Click on this link 

https://www.cimotorhomes.co.nz/fiat_service_centres