India Post — Postman demanding money at home

Address:	Saran, Bihar, 841101
Website:	indiapost.gov.in

From bihar (Sonepur) pin 841101
The new postman in the past few months is coming to deliver on time but demanding way more money (Tip) to deliver the letters (Aadhar, pan, passport etc.) like 150 to 500. I tried giving him 20 to 50 as tip but says no and demands more. Today i tried making him understand what i thought but instead of listening he starts giving threats and rejected the tip and went off (Pissed).
Please do something @841101.