Sorry, I never saw this post until now, and I suspect it's already been dealt with via another channel, but I'll answer anyway for the benefit of anyone else that has the same issue.
Registering an Add-On does NOT download it for you or install it for you. You are supposed to use the download links I send you to download and install the Add-On/s yourself, as per the installation instructions in the PDF that is included with every download.
If you received a download link but no registration code, you probably missed the note at the bottom that says to use the "Claim from server" button to register the Add-On/s. I typically do this when sending out mass emails to dozens or hundreds of backers.