Apex domains cannot have CNAME records.
Question and response
Question
dig bitency.net. NS
Answer
bitency.net. 5 NS dns52.cloudns.net.
bitency.net. 5 NS dns54.cloudns.net.
bitency.net. 5 NS dns53.cloudns.net.
bitency.net. 5 NS dns51.cloudns.net.
bitency.net. 5 NS ns1.bitency.net.
Authority
The response has no authority records.
Additional
ns1.bitency.net. 5 A 37.72.98.4
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0