You cannot delete your account.
Ask them manually by going to http://digitaltunes.uservoice.com/ and clicking “Contact support”, on the right side of the screen. Briefly explain why you want to have your account removed and be sure to include your personal details (username, email address you used for signing up).
If you get no response, anonymise your account. Read the tip below for more information.
URLS:
http://digital-tunes.net