way to cancel reinstated line and requisition?

Summary:

Hi everyone, 

I’m encountering an issue with cancelling a requisition in Oracle. Here’s the situation: 

• A requisition was created and subsequently approved. 
• The requisition was converted into a purchase order (PO) with two lines, and the PO was approved. 
• One of the PO lines was cancelled with the option “Cancel Unfulfilled Demand - NO.” This action resulted in the creation of a reinstated line. 

Currently, the "Cancel Requisition" option is disabled in the requisition header, and as a result, I am unable to cancel the requisition. 

Can anyone advise on how to proceed with cancelling this requisition under these conditions?