Can't close notification

AVG sometimes sends me an ad/notification that I can't get off my computer.  The current one cannot be closed and doesn't go away even with a restart.  The title is AVglobal something and is garbled by overwriting.  How can I get rid of it"?

Hello Frances,

I am sorry to hear that.

Please send me the screenshot http://avgclick.me/getscreenshot of the AVG pop-up you receive. We will check the same and assist you further.

Hello Frances,

I am sorry to hear that.

Please send me the screenshot http://avgclick.me/getscreenshot of the AVG pop-up you receive. We will check the same and assist you further.

Frances, For your info, just in case that you are unaware, you can post the screenshot here in your topic. Click on 'Answer' & then click on the 'Image' [mountain symbol] & follow the instructions. 
AVG Guru