India Post — complaint against postman of libaspur

This is to inform you about the postman of my area. I live in libaspur, delhi–110042. The postman of this area is not performing his duty properly. He never delivers a parcel. As you know pan card comes by post. He return all the pan card back without delivering. And when we visit him in post office he becomes aggressive. So i want u to take some action. This will be a great help. And pls reply me.
Thank you