There are a couple of things that could cause this issue, and the best way to find out why this is happening is to go to Help > About from the top menu in Fundy Designer to see which email address you're logged in with, which version of the software you're currently running, and if your license is being recognized.
1. Double check that the email listed here is the one you used to make your purchase. If it is not, click Ok, then go to Help > Log Out and log in with the correct email. That will resolve the issue.
2. If your email is correct, but you aren't seeing your licenses here, then you're probably not using the latest build of the software. Don't worry, a quick update should resolve the issue. The update feature built into the software will not work, so you will need to download the latest build of the software here: http://fundydesigner.com/downloads/
Make sure to scroll for the version of the software that you own a license for: v6 or v7. Don't worry, your work won't be affected. Once you reinstall Fundy Designer, you should be able to log in with your email and password without issue. If you cannot remember your password, you can reset it in the software!
3. If your email is correct and you're on the latest version, perhaps your order did not go through. Contact the support team and they can look into your inquiry further.