BADI ME_PROCESS_PO_CUST~POST how to read Item service data

Hi,

  In the Service Purchase order, I want to add some validation on the basis of service item, this is working fine at method PROCESS_ITEM

as I am able to read the service data as per below code

    lr_po_item_handle ?= im_item.

     CALL METHOD lr_po_item_handle->get_data

       IMPORTING

         ex_data = ls_mepoitem

       EXCEPTIONS

         failure = 1

         OTHERS  = 2.

     if ls_mepoitem-PSTYP = '9' and

        ls_mepoitem-BANFN is NOT INITIAL and

        ls_mepoitem-bnfpo is NOT INITIAL.

     CALL METHOD lr_po_item_handle->if_services_mm~get_srv_data

       EXPORTING

         im_packno = ls_mepoitem-packno

       IMPORTING

         ex_esll   = lt_esll

     "  ex_esuh   =

      " ex_esuc   =

       "ex_eskl   =

       EXCEPTIONS

         failure   = 1

         OTHERS    = 2.

       delete lt_esll where pln_packno is INITIAL.

but this get triggered when press enter, but if we click directly on 'SAVE' button after changing the quantity at service level,

method 'PROCESS_ITEM'  does not getting trigger

so same logic I want to add in POST method, in this I am able to read the line items details as per below logic.

     lr_po_header_handle ?= im_header.

     CALL METHOD lr_po_header_handle->if_purchase_order_mm~get_items

       RECEIVING

         re_items = lt_po_items.   " Table with PO Items

      loop at lt_po_items into ls_po_items.

        clear : ls_mepoitem.

        ls_mepoitem = ls_po_items-item->get_data( ).

        append ls_mepoitem to lt_mepoitem.

       endloop.

NOW in lt_mepoitem I am getting all the line item details,

How to read the service data from here?

regards,

zafar