Order is getting cleared through BAPI_SALESORDER_CHANGE

Hi All ,

I want to clear Billing Blocks. So i achieved this by using BAPI: BAPI_SALESORDER_CHANGE. But unfortunately order is getting cleared for all the line items which am clearing  billing blocks. I am updating only billing blocks through BAPI, In header i marked Billing Block and for item also Marked only Billing Block. Any Idea on this ??

Regards,

Ravi Kiran Sankuru.