Can't switch back to Light from Pro

I purchased a license from through Humble Bundle. After I redeamed my token and did the install I switched to Pro to checkout the additional features. Now that it has expired I cant switch back to the Light version. I tried using the Lost Registration link but it says that "The email address you supplied could not be found in our database."

Any help you can provide will be greatly appreciated.

When the token was redeemed a Light certificate should have been emailed to you. If you still have that email, the certificate file within it will still work.

If you don't have the email or it never arrived, please contact Sales with any details you can provide to locate the account and certificate details, and they should be able to help from there.