I also replied to your ticket, but for future reference I'll explain what happened here as well 🙂
After upgrading, the subscription was correctly added to the account. Usually after subscribing you should see a screen to select a site to attach the subscription to.
In some situations this doesn't happen and you get redirected to the subscription page instead. When you refresh the page, it should show that you have a valid subscription (however, in rare cases it can take a few minutes before it appears).
Then, you can go to your site-overview (
My sites in the menu), select the site you want to be upgraded, click on
Site plan and select the subscription that is available.
Now save the changes and the site should have access to all premium features 🙂
Hope it helps! If there any further questions, make sure to let us know 🚀