Apex domains cannot have CNAME records.
Question and response
Question
dig dont360buy.com. NS
Answer
dont360buy.com. 3 NS dns2.p01.nsone.net.
dont360buy.com. 3 NS dns4.p08.nsone.net.
dont360buy.com. 3 NS dns1.p12.nsone.net.
dont360buy.com. 3 NS dns3.p03.nsone.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0