Apex domains cannot have CNAME records.
Question and response
Question
dig meganet.com.pl. NS
Answer
meganet.com.pl. 5 NS ns1.meganet.com.pl.
meganet.com.pl. 5 NS ns2.meganet.com.pl.
Authority
The response has no authority records.
Additional
ns1.meganet.com.pl. 5 A 91.231.61.238
ns2.meganet.com.pl. 5 A 91.231.61.243
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0