Product status not getting updated for product in CRM web ui

Hi CRM experts,

I am trying to update product status as active or inactive from the prsntation server by giving an input file having two fields product id and status.

I am using following code to update the same:

Data declaration:

lr_query_prod TYPEREFTO cl_crm_bol_dquery_service,
lwa_sel_tab      TYPE genilt_selection_parameter,
rv_result        TYPEREFTO if_bol_bo_col,
lr_product_ent      TYPEREFTO cl_crm_bol_entity,
lr_prodstat  TYPEREFTO  if_bol_bo_property_access,
lr_core TYPEREFTO cl_crm_bol_core.

          lr_core = cl_crm_bol_core=>get_instance( ).
          lr_core->load_component_set( 'PROD_APPL' ).

  lr_query_prod = cl_crm_bol_dquery_service=>get_instance( iv_query_name = 'ProdAdvSearchRgProducts' ).

Loop at it_file  into wa_file.           

IF lr_query_prod ISBOUND.

            lwa_sel_tab-attr_name = 'PRODUCT_ID'.
            lwa_sel_tab-sign = 'I'.
            lwa_sel_tab-option = 'EQ'.
            lwa_sel_tab-low = wa_file-product_id.

            CALLMETHOD lr_query_prod->add_selection_param
              EXPORTING
                iv_attr_name = lwa_sel_tab-attr_name
                iv_sign      = lwa_sel_tab-sign
                iv_option    = lwa_sel_tab-option
                iv_low      = lwa_sel_tab-low.

            rv_result = lr_query_prod->get_query_result( ).
            IF rv_result ISBOUND.
              lr_product_ent ?= rv_result->get_first( ).

              IF lr_product_ent ISBOUND.

                lr_prodstat = lr_product_ent->get_related_entity( iv_relation_name = 'ProductStat').
                IF lr_prodstat ISNOTBOUND.
                  lr_prodstat = lr_product_ent->create_related_entity( iv_relation_name = 'ProductStat').
                ENDIF.

                IF lr_prodstat ISBOUND.
                  CALLMETHOD lr_prodstat->set_property
                    EXPORTING
                      iv_attr_name = 'STAT'
                      iv_value    = wa_file-status.

                  CALLMETHOD lr_prodstat->set_property
                    EXPORTING
                      iv_attr_name = 'INACT'
                      iv_value    = space.

                  CALLMETHOD lr_prodstat->set_property
                    EXPORTING
                      iv_attr_name = 'STSMA'
                      iv_value    = 'ZPRODUCT'.

                  lr_core->modify( ).

                ENDIF. "IF lr_prodstat IS BOUND.
              ENDIF. "IF lr_product_ent IS BOUND.
            ENDIF. "IF rv_result IS BOUND.
          ENDIF. "IF lr_query_prod IS BOUND.

ENDLOOP.

But this is not updating anything.

Please guide me what is wrong in this and what things i need to check.

I am new to CRM ,so any inputs/help would be higly appreciated.

Attaching the sample screenshot of the field in web ui.