SAP PO Approval + Custom Workflow + Decision Step

Hi Experts,

We are using decision step in custom workflow and having action approve/reject. We are able to see the work-items generated in standard Approve PO Fiori app . Once we take the action on the item , the decision step do not get completed.

In standard workflow of PO the activity task is getting completed  through terminating event but since we are using decision step , the workitem is not getting completed hence not getting refreshed from worklist.

I tried implementing the BADI  ( I have called FM SAP WAPI WORKLFOW COMPLETE ) to complete the workitem but still it is not getting called.

Please suggest .

Thanks

Abhijeet