Can't Remove AVG Antivirus Completely (MAJOR Problem)

I am having trouble uninstalling AVG Antivirus, I have sent the application to the trash and deleted but I found a directory to /Library/StagedExtensions/Applications/AVGAntivirus. I have tried to perform a root removal, terminal removal, force removal but it is classed as 'needed by macOS' which it is not. I really need this removed as it is a pest and keeps opening multiple unneeded applications (typical from a 3rd party site).