Purchase order -- Closed for invoice- accidentally close one line


Does anyone know, when you process the Drop shipment PO and SO in SAGE 500, accidentally closed one of the lines and post it in the Receipt of Goods

However, we still have part of the items no receive.  does anyone know how can I open this line? the problem is I can't match the total amount with the invoice.

Because the client sent me the invoice by three different times.