This View can be used to find out if you imported the correct commission data or if you imported the same data twice. If you want to trash all data that you imported for a supplier or for all suppliers you can also choose to trash some items on the Import data page.
Top Menu >> Import Data >> ...More >> View Imports
It will list out your imports and will sort them out based off of Supplier and import method. Click View items will filter out all items imported for that Supplier.
Click ...More >> Trash these items