deleting item from work flow

Dear expertises,

Could some body so kind to help me in the following.

In one user of my client have unreleavent item in his SAP inbox.

Some item are event & some are massage.

When I try to delete the item using functional module RH_SWWUSERWI_DELETE_FOR_WI it delete from his inbox for a moment.

But in the next day again it appear in his inbox.

I have workflow administrator authorization.

Kindly help me to solve the above.

Regards,

sp sahu