Apex domains cannot have CNAME records.
Question and response
Question
dig sonichost.co.za. NS
Answer
sonichost.co.za. 5 NS ns3za.cybercircuit.co.za.
sonichost.co.za. 5 NS ns4za.cybercircuit.co.za.
sonichost.co.za. 5 NS ns1za.cybercircuit.co.za.
sonichost.co.za. 5 NS ns2za.cybercircuit.co.za.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0