Item Charge Assignment on Posted Invoices

I have a situation where in the PO is raised, Received and posted to the vendor. While posting the invoice, the accounts guy forgot to add the Item charges pertaining to that vendor.

Now When i create an invoice with 100 Rs (which is item charge assignment) and used function-> get receipt lines and did the item charge assignment. Now when i press F9 for statistics window, the invoice amount is showing which is including the Receipt lines value. But i need only 100 to be accounted to the vendor.

I dont want the receipt lines to be included in invoice value as it is already invoiced and i want only that 100 to be invoiced again to that vendor