India Post — Postman not delivers letter

Address:	Kolkata, West Bengal, 700007
Website:	www.indiapost.gov.in

Hello sir
I live at barabazar kolkata. My problem is my post never comes to me at my place. The postman delivers it anywhere and to anyone even he gives my parcels and bank confidential letter to anyone in the area. Some people give them to me and some dont. In past some of my parcel sent through india post deliver to strangers by postman which never receive by me.
Plz suggest me to take any step so that postman gives my letter and parcel to me or to my house not to anybody.