Invoice Coreection request for Debit Process

hi

I wanted to use the Invoice correction Request for the Debit Process

I have invoices customer for 10 pieces instead of 12 Pieces , so I need to correct the Invoice and need to get money for the remaining 2 qtys.

Customer wants to do the same throught Invoice Correction Process.

The Standard Process Allows to create the Crdeit Memo in negative Posting in this Above case,

How could i do correct postings by debit memo

Because I tried creating new INvoice correction document and did copy control , by when i create the invoice , the debbit memo is for 22 pieces , pls

advice me on correct confoguration