I have purchsed a theme but it doesn't appear in the extentions after upload

Hello,
I have purchased Theme for my store and I have tried many times to upload the filles with Filezila in the root directory of Opencart, but nothing happens. In the Extentions drop down menu in "modules" I don't see the new Theme!

What should I do to install it? Is there another option to change my theme to the purchased one?