India Post — Abstraction of contents of speed post article

Address: Bangalore, Karnataka, 560066

Website: www.indiapost.gov.in

I have sent a consignment (weight=115gm)containing some important documents through speed post.It was perfectly packed in an envelope. i got the counter foil from whitefield p.o (560066) Bangalore.
when i received it at destination it weighs only 71gm and the packing is also altered.Some of the important documents are missing from it. It can push me in big trouble i[censored]sed in illegal acts.
I may need to lodge a FIR for this incident.It is really a very bad experience from indian speed post.
I have registered the complaint on india post portal also with Complaint no.[protected].