From their forum: For security reasons, we do not remove accounts. Source: http://www.twickerz.com/forum.php?topic=36744 which seems to be based on their ToS/PP.
So, bad luck, but this may especially be tricky as far as you submitted financial data. Alternatives: delete/anonymise as much as you can, and/or contact them with your deletion request anyway: http://www.twickerz.com/?view=contact&t=new
URLS:
http://www.twickerz.com/