You can view your fare regulations when you go to this site https://www.latam.com/en_us/apps/personas/reissue#booking-search

Anyways, it seems there is a charge of 200 NZD for the refund:

CANCELLATIONS
ANY TIME
CHARGE NZD 200.00 FOR REFUND.
TICKET IS NON-REFUNDABLE IN CASE OF NO-SHOW.
NOTE -
REFUND MUST BE COMPLETED BEFORE DEPARTURE TIME OF
THE ORIGINAL FLGHT -OTHERWISE- IT WILL BE
CONSIDERED NO-SHOW AND SUCH PENALTY/RESTRICTION
WILL APPLY.


You can ask for the refund here http://www.lan.com/cgi-bin/devoluciones/formulario_devoluciones.cgi


Good luck!