Apex domains cannot have CNAME records.
Question and response
Question
dig waterbedstores.com. NS
Answer
waterbedstores.com. 5 NS ns-708.awsdns-24.net.
waterbedstores.com. 5 NS ns-1289.awsdns-33.org.
waterbedstores.com. 5 NS ns-1576.awsdns-05.co.uk.
waterbedstores.com. 5 NS ns-532.awsdns-02.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0