numerous open inbound deliveries created wrt scheduling agreements

Hi,

we use Inbound scheduling agreements to procure materials from vendor. Vendor sends us the inbound DESADV idocs (ASN) to notify the goods arrival. Suppose we ordered 1000 Qty of Material, the vendor sends us asn idocs 100 qty each which amount to more than 1200. but sends only 1000 qty of goods. Each asn idoc creates an inbound delivery. so 2 deliveries are created which are extra - for which the goods are not delivered. Now is there a way where we can put a check in the idocs , so that when extra quantity idoc comes into the system, they fail. If its a PO, we can check the scheduled quantity. But since we are using the scheduling agreement and quantity can be adjusted for the next time, please let me know how to stop creation of inbound deliveries for which we have not received goods. If not, is there a way to delete open inbound deliveries at a time (mass delete).