I was able to login to your site and it seems that you already have the site installation validated. Since you are still not getting the updates, please try to Revoke your site's validation then revalidate the site again. Here are the steps in Revoking a licenses:
If you are not seeing the revoke validation option on the top of the page, try scrolling to the most bottom part of the page.
Once validated again, try going to the Wordpress admin's updates dashboard and click on Check Again.
Hope this helps.