We are sorry but 1 license can be used for the 1 project. And the project, where you used it, is still active https://sun-catcher.co.uk/
Refund policy allows giving refund only if theme quality does not meet the description or you found theme bugs that can’t be fixed https://themeforest.net/page/customer_refund_policy
Refund can’t be given if you decided to change the client or your client decided to change the developer but still uses the theme for his project. In this case, he should buy the other license, deactivate your license from theme options and activate the new one for his site.
Theme author can’t disable the license. You may try to contact Envato support with this request. Or buy another license, provide us with purchase code and then submit refund request for the previous one. Then we’ll be able to accept it.