I have a PO that I am trying to cancel.  All of the lines show cancelled, the delivery remainder is blank, the PO itself is cancelled. 
 
When I try to remove a line it gives the error:
  "The items are Purchased, Received or Registered."
  "Quantity cannot be reduced because the remaining update quantity changes sign."
 
The delete button on the PO is not available.  I cannot submit to workflow because the lines were entered wrong.  I cannot finalize the lines on the PO because the lines are not "Invoiced, or Canceled" despite the line being in the canceled state.  I cannot edit the line to 0 qty without getting the same error as above.
 
Update Line allows me to update the Delivery Remainder Qty, but registration is blanked out.  
 
As far as I can tell, this PO has not been received or invoiced.
 
The end goal is to get this PO into a cancelled state without being in draft, as the PO is showing up in the users workflow for PO's in Draft.