Apex domains cannot have CNAME records.
Question and response
Question
dig hostserv.co.za. NS
Answer
hostserv.co.za. 5 NS linus.ns.1-grid.co.uk.
hostserv.co.za. 5 NS linus.ns.1-grid.net.
hostserv.co.za. 5 NS linus.ns.1-grid.com.
hostserv.co.za. 5 NS linus.ns.1-grid.co.za.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0