India Post — loss of article

Address:

Muzaffarpur, Bihar, 842004

My article was posted from kachari katra which is 211002 under allahabad do. It was about to reach 842004 under muzaffarpur spc. But i didn't get my article and on being asked they said it was lost before reaching allahabad nsh office.
Speed post tracking number - eu[protected]in
Transaction date - 9th of december, 2017

I request to look into the matter and help in solving the problem asap.
Kachari katra speed post office manager phone - [protected]