This is modified class for the woo commerce, There were an issue when admin cancel the order, Woo commerece didn't reduce the stock as well total_sales. What you need to do.
1:> Find this class file and open.
2:> Ctrl + A and Delete All code (If you want to take this code back up you can save this code to your Hard drive )
3:>open this link (This is modified class for the cancel order which will manage stock and sales as well for the order cancel.
Enjoy now it will automatically manage Inventory Management Over Cancel Orders as well Total-Sales.