AVG internet security will not uninstall

I have always had AVG antivirus free. I opted in the trial AVG internet security. It has expired and I decided to go back to AVG free. It will not uninstall. I have followed the instructions to go back to avg as prompted and when I restart my computer, there it is again and I am unprotected. I have tried to manually uninstall  and reinstall avg free … same results. I will never do another trial in my life!! I just want my basic AVG free edition back. Can you help me?

Hello Sherry,
You had contacted our chat support team about this issue. They have sent you an email, you can reply to that email if you need any further assistance.
Regards,
Alok.

Hello Sherry,
You had contacted our chat support team about this issue. They have sent you an email, you can reply to that email if you need any further assistance.
Regards,
Alok.