I am not with Laminar Research; just a flight simmer.
This is not the site to complain about receiving of your product key. This site is for those flight simmers experiencing problems in running the software. As Llaslo has indicated the contact should be mad direct with Laminar Research at the following link at email@example.com
If you downloaded the demo version there is no product key required or made available to use the software. The good news is that when you have purchased the software and then apply the product key when asked then the full version opens for your use. Be warned that you need to have a permanent internet connection and there will be occasions when you will be asked to provide your product key. This is a safeguard to ensure you have a legal copy of the software.
If you are wanting to purchase add-on aircraft then start with www.X-plane.org which is a site just for x-plane users. This site has no connection with Laminar Research, the developers of the X-Plane software.
In addition, Laminar Research does not market additional aircraft over and above the aircraft provided within the software.
Hope this helps and persuades you to move forward and not take a retrograde step backwards.