Open the 
Posted Return
Receipt window. and browse to the relevant document.
Select the line or lines you want to correct and click Functions, Undo Return Receipt.
If you have made an incorrect quantity posting, that is if you have made a return order with, for example, the wrong number of items and posted it as received (but not invoiced), you can undo the posting.
Open the Posted Return
Receipt window. and browse to the relevant document.
Select the line or lines you want to correct and click Functions, Undo Return Receipt.
The program will now insert a corrective line in the posted document and the Returned Qty. Received and Return Qty. Rcd. Not Invd. fields on the return order are set to zero. If the quantity was received in a warehouse receipt, the program will insert a corrective line in the posted warehouse receipt and, if the quantity was only partially received, update the Qty. to Receive on the warehouse receipt.
Go back to the return order and click Functions, Reopen to reopen it.
Correct the entry in the Quantity field and post the order.