Closing Credit Memo Request

Hi Gurus

I would like to know how can I close open Credit/Memo Requests like we close open Sales Orders by using Reason for Rejection.

I have tried closing it by putting Billing block, both at header and item level, but it is still showing Open in the document flow.

I even tried closing it by inserting Reason for Rejection at line item level but in vain.

Any idea?

Thanks