Hi,
What I would do in your case is:
Log in to my.vmware.com and then under support (top right menu) select license tracker tool.
This will open a new tab in your browser.
You can enter your license in there and it will tell you if it is valid.
Then on the same website go to menu Products (also right menu, but now most left item) then select "Product registration"
Enter your license. That should work.
If you can register it down there, but not on your product (Fusion / Workstation), at least the license key is already in the system under your account and you can raise a ticket from there.
--
Wil