Use your cPanel or FTP to install the Theme4press core plugin if you have trouble installing it.
Please provide FTP or cPanel access details in private reply, if you need my help to install the plugin. I will also need your WordPress admin access to activate it.
Some of the design has been changed by the Author, such as the content box button and bootstrap slider.
For refund request, you can contact my employer via our contact page. https://theme4press.com/contact/