Apex domains cannot have CNAME records.
Question and response
Question
dig h20.seohost.pl. NS
Answer
h20.seohost.pl. 5 NS ns1.microhost.pl.
h20.seohost.pl. 5 NS ns2.microhost.pl.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0