Apex domains cannot have CNAME records.
Question and response
Question
dig kingston-internet.net. NS
Answer
kingston-internet.net. 5 NS bison.kingston-internet.co.uk.
kingston-internet.net. 5 NS ibex.kingston-internet.co.uk.
Authority
The response has no authority records.
Additional
ibex.kingston-internet.co.uk. 5 A 212.50.160.28
bison.kingston-internet.co.uk. 5 A 212.50.161.28
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0