Apex domains cannot have CNAME records.
Question and response
Question
dig coza.net.za. NS
Answer
coza.net.za. 4 NS ns2us.dns.business.
coza.net.za. 4 NS ns.coza.net.za.
Authority
The response has no authority records.
Additional
ns.coza.net.za. 4 A 206.223.136.200
ns2us.dns.business. 4 A 147.135.106.236
ns.coza.net.za. 4 AAAA 2001:43f8:30:0:0:0:0:200
ns2us.dns.business. 4 AAAA 2604:2dc0:200:2eb:0:0:0:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0