Do you mean you set the 'Disable active corners' setting to 'All' in Classic Start Menu settings -> Windows 8 tab and yet the Charms are showing?
Are you on a laptop with a touchpad? Even if Classic Shell disables the charms for the mouse hot corners, Microsoft made it so that the charms get activated via touchpad gestures. This is controlled by the touchpad drivers. Check in your Mouse Control panel or anything related to Touchpad drivers which loads at startup. It may have an option to disable swipe gestures for the touchpad.
Here are two common touchpad vendors' control panels (integrated with the Windows mouse control panel)
You can also try Skip Metro Suite: http://winaero.com/comment.php?comment.news.103 which kills the Charms hidden window everywhere including inside the Modern UI.
On Windows 8.1, you can try Winaero Charms Killer: http://winaero.com/comment.php?comment.news.219
