return Billing document number in BAPI

Hello,

I am working on BAPI_BILLINGDOC_CREATEMULTIPLE.

This is returning Invoice number and Billing document number. But when I am using huge volume data then it is not returning billing document number even I use BAPI_TRANSACTION_COMMIT after call BAPI_BILLINGDOC_CREATEMULTIPLE.

Without WAIT for 5 seconds, or space in it, is there another way to get billing document number?

This we are returning back to proxy program.