Ability to cancel purchase orders even if marked as partially delivered Merged

We have a lot of purchase orders which we cannot remove the live status from, as we get an error message this item has been partially delivered. As you have to mark goods as received to update a purchase order as completed, this may have been ticked in error in quite a few cases. It would be helpful to be able to either reverse goods received or to cancel/complete an order that had been marked as goods received,