Over delivery of a sales order-status still shows "not delivered"

Hi Friends

I have a problem with sales order . Total quantity in order is 10, even then system allows me to make 2 or more deliveries of total with more than 10 quantity .

Following option I have tested but all in vain.

1. In copy control at item level ( item category is TAN) document flow box is checked and Pos./neg. quantity column has value "0". If I take here "" then system don't allow me to make partial deliveries i.e 2 deliveries of 5 quantity each. It says " there is no quantity available for delivery or the item is not relevant for delivery. I can make only one delivery with 10 or less quantity with "" sign

If I take "O" in Pos./neg. quantity field then it allows me make as many partial delvery with more than 10 quantity, which is wrong

Order status always shows " No delivery" even if deliveries made and PGI done

2. In item category checked complition rule field with "A", "B" and "c" option still no effect and document flow shows "being processed "

Pls let me know whts the problem

Thanks