TNC FlipBook NOT License Working

I purchased a TNC FlipBook and have a License, but it is not working. Where do I get assistance? It used to work, but now it does not accept my "Item Purchase Code. " What is going on?

If you downloaded the item from Elements, as Elements and Marketplace licenses are different, it’s not gonna work.

If the license is from Marketplace for newly purchased item, it may take couple of hours for the license activation. You can try again later.

As you can see, I entered the purchase code and received the following: Congratulations! Your site is now registered.

I entered the purchase code and got the message: ‘Congratulations! Your site is now registered.’ But every time I try to use it, it keeps asking me to register again! What’s going on?"

Please, remove the email/purchase code from public.
Contact item author for the support