Apex domains cannot have CNAME records.
Question and response
Question
dig user.veloxzone.com.br. NS
Answer
user.veloxzone.com.br. 1 NS ns4.telemar.net.br.
user.veloxzone.com.br. 1 NS ns2.telemar.net.br.
user.veloxzone.com.br. 1 NS ns9.telemar.net.br.
Authority
The response has no authority records.
Additional
ns2.telemar.net.br. 1 A 200.202.193.74
ns4.telemar.net.br. 1 A 200.222.0.35
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0