MTNL Delhi — vert high and faulty bill

Address:

New Delhi, Delhi

i have a mtnl broadband combo plan of freedom 597.in the month of February there is a promotional offer in which they reduce the modem and installation charges upto rs1000 when booking the internet before 5th february 2015 so i book the internet but on the first month of internet they give me two bill of 697rs each i complaint this to sanchar hat but they did not respond the said that this bill is right but before i booked my internet i asked to the mtnl officers about the promotional offer the said that you did not give modem charges and installation charges you give only 597 rs with cpe modem charges and with service tax but after this they give a bill of only modem and installation charges and other bill of my internet usage. they are such a fraud i complaint this but they did not responded. please give me suggestion about what i do about this.