Delete Rejected Items

I made a Subcontrating Purchase Order.

I ordered 2500 items (so I delivered the raw materials to that quantity), but the final production was 2400 items (100 items were lost).

When doing the Purchase Receipt, I entered Reject Qty = 100. Thats ok?

I must complete the Rejected Warehouse, but the items are lost! How am I supposed to do this?

Sorry for the english.