Apex domains cannot have CNAME records.
Question and response
Question
dig rtn.net.do. NS
Answer
rtn.net.do. 5 NS ns1.accountsupport.com.
rtn.net.do. 5 NS ns2.accountsupport.com.
Authority
The response has no authority records.
Additional
ns1.accountsupport.com. 5 A 65.254.254.104
ns2.accountsupport.com. 5 A 65.254.254.105
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0