As can be read on http://www.kongregate.com/forums/1-kongregate/topics/24106-delete-my-account
…it is impossible to delete your account. You can only send a request for a permanent ban (!?) using the feedback link shown. Sorry, too vague for even a ‘grey list’ label.
URLS:
http://www.kongregate.com
http://www.kongregate.com/feedbacks/new