Procurement Contracts and Return to Vendor Question

After creating a procurement contract to a Single PO, receiving then creating and processing an RTV for the inventory item, we do not see any impact on the open quantity on the contract. For example: Contract is for $10,000 worth of a $10 item. We place an initial PO order of 100 pieces, receive them in, reducing open amount to $9,000. We create and process an RTV for 50 of the 100 pieces received, as a REPLACE RTV. We expected the open amount to increase back up to $9,500, but it remains as $9,000.

Any thoughts?

Thanks,

Dan Rotermund