Hi,
The old site seems to be still active on the update server. On the new site, under the Updates & Help panel if you enter the purchase code and the old site details, you should be able to deactivate it remotely as well.
Step 1 (site URL without http://): https://i.imgur.com/2f59zlM.png
Step 2 (after 30 minutes cooldown): https://i.imgur.com/iLMqnOk.png
Let me know if that does not work, and I will de-activate it manually.