Apex domains cannot have CNAME records.
Question and response
Question
dig telecel.com.py. NS
Answer
telecel.com.py. 4 NS ns3.telecel.com.py.
telecel.com.py. 4 NS inet2.telecel.com.py.
telecel.com.py. 4 NS inet3.telecel.com.py.
Authority
The response has no authority records.
Additional
ns3.telecel.com.py. 4 A 186.17.19.255
inet2.telecel.com.py. 4 A 186.16.16.6
inet3.telecel.com.py. 4 A 186.17.17.7
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0