BAPI to release billing block of debit memo request

Hi

I need to create Credit /Debit memo for this I m

1. using FM  SD_SALESDOCUMENT_CREATE to create Credit /Debit memo Request.

2. using BAPI_BILLINGDOC_CREATEMULTIPLE to create Credit /Debit memo.

by using above steps I m able to create Credit Memo( there is no need to release the billing block).but in case of  Debit memo ,return table of BAPI_BILLINGDOC_CREATEMULTIPLE  giving 'The document is blocked for billing' .(also when I  released the billing  block in TC V.23 this BAPI still give the same) .

For this I need a FM or BAPI to release the billing block of debit memo request.

plz help me out.