Hello,
Sorry to hear you are having issues. Please check this guide. https://forums.stardock.com/484254/getting-your-products-and-keys. A lot of time I see user simply misspelled their email account or typo. Or, If you did pay via paypal, check with email that linked to paypal. Do let us know if you still need assistance.
Thanks
Basj,
Stardock Community Assistant.