Airtel — billing issue and overcharging amounts

Address: 560100

I have taken an iphone with airtel a year back with rs 1999/- plan per month, where rs. 1334/- is emi and rs. 665/- as rental. The airtel is charging this amount every month as part of my bill, at the same time their finance team (Bajaj finance) is deducting the same emi from my bank account from last april. I have informed this with airtel many times, but no action from them yet. Also airtel has informed that my contract is already ended by june 2017, still deducting the emi two times monthly. They have adjusted few amount in my earlier bills, but i have asked them to stop. Hence they haven't paid the extra amount of last 3 months back to me. At the same time, airtel has charged me emis after my contract period. The total amount deducted extra is 3 months of emi deducted from my bank account + 6 months of emi part of my bill after contract. I have escalated this issue many times, but no action yet from airtel. I am following with airtel most of the days, and it is affecting my life with lots of stress and tension. Please help