Good thing you didn't pay.
Bad thing you have let him control your system.
It seems to me this was not someone from Alwill.
Use <url=https://support.avast.com/]THIS[/url] to contact Alwill if you have to/want.
I suggest you run a full bootscan with Avast and after that malwarebytes.
iBryte Optimum Installer is an installer which bundles legitimate applications with offers for additional third party applications that may be unwanted by the user. Such third party applications are typically installed onto users’ computers by default, but may include an option to ‘opt-out’ during or after the installation process.