From their help desk (http://support.transifex.com/customer/portal/articles/1052765-how-can-i-delete-my-account-)
For technical reasons, the deletion of accounts is not supported. However, we can deactivate an account upon request.
Use this form to request deactivation of your account: http://support.transifex.com/customer/portal/emails/new
URLS:
http://transifex.com
Please note that AccountKiller.com is not associated with the business listed on this page. AccountKiller provides easy-to-understand instructions and guides on how to cancel charges and relationships from the list of businesses on our site, we have no affiliation with these businesses.