Vipin,
Assuming the GR was done; first you will have to do MBST to take care of the incorrect posting.
You haven't specified its components that were faulty that were supplied earlier OR
Vendor sent defective finished product.
In any case; you are not able to cancel the doc.; then you may want to create Return PO and have the Vendor send a credit memo.
Since you've mentioned continous process; following Returns will be clean and clear.
Regards.