I can't refund or access the payment details of your purchase, because Answers Informer isn't the home of the developers. However, I can forward you to the correct section on the developer's website. You then have to use the available menus to report this issue and if everything settles, money will be wired back to your account.
Support page: http://www.ytddownloader.com/contact_us.html
Tip: Check the SPAM folder on your email because the license key could be there instead.