Apex domains cannot have CNAME records.
Question and response
Question
dig vodafone.co.nz. NS
Answer
vodafone.co.nz. 4 NS ns1.vnue.co.nz.
vodafone.co.nz. 4 NS ns2.vnue.co.nz.
Authority
The response has no authority records.
Additional
ns1.vnue.co.nz. 4 A 202.73.206.15
ns2.vnue.co.nz. 4 A 202.73.198.15
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0