Apex domains cannot have CNAME records.
Question and response
Question
dig imcsas.com.co. NS
Answer
imcsas.com.co. 5 NS ns4.colombiahosting.com.
imcsas.com.co. 5 NS ns1.colombiahosting.com.
imcsas.com.co. 5 NS ns2.colombiahosting.com.
imcsas.com.co. 5 NS ns3.colombiahosting.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0