In order to uninstall a program from you computer, you can try using the Windows uninstaller. It's located in Start > Control Panel > Add or Remove Programs (Windows XP) or Programs and Features (Windows 7). If you have problems and you can't uninstall a program, use Revo Uninstaller. This tools is specially designed to remove any application by forcing it to unsintall.
In order to obtain a refund, you must contact the developer. You can find all the necessary contact information on the official website.