Hi @vashdenarada, Let me help you on this first to make sure why this is not working for you.
You have multiple option to get custom css working
1) Boss theme options for custom css
2) Child theme style.css
3) Child theme custom.css
4) any additional plugin to add custom css like https://wordpress.org/plugins/simple-custom-css/
Each of them are working options. You just need to add correct css inside them.
If you have set your mind for refunds, Please submit your request from our contact page, our team will process it
Regards