Thanks for asking and I am really sorry for the trouble you are facing because of unsuccessful update.
I tried opening the website that listed on your licence page but it seems that you have activated under construction page. Have you tried updating manually by uploading theme files using FTP? It's mentioned in the ticket but it's not very clear that's why I wanted to confirm that? If not, please take a look at following resource to update theme manually as there can be some corrupted files while updating:
If problem is still there, please share WordPress and FTP login details in a secure note for us to take a closer look.