Panalty for bills that are paid in time

Location/place: Arnetha, K.Patan, Bundi (rajasthan)

Name of company/service: BSNL Landline

Sir/Madam
I am a user of BSNL broadband. My number is 07438-267091. I have paid I my monthly bills in time, but even than the company has charged panelty for late payment in many of my bills, including the most current bill
My mobile number is 9950033380