Airtel 4G — Refund not given back

Address:	Bangalore, Karnataka, 560029
Website:	www.airtel.com

I Have surrendered AIRTEL 4g Connection on 26th Dec, 2015.After 24 days airtel got back to me to submit documents for refund, which was forwarded to them 3 times. Airtel did commit that my refund will happen on 6th fEB, and the date revised was 12th feb and again it was further revised to 15th feb, 2016.Till date airtel has not refunded back my Rs.3900, even after submitting all documents.The customer care just notifies that i will get reply in 72 hours, however its been near to 55 days but airtel does not seem to refund my money. Airtel is not giving me the details about the money, even after 35 emails exchange.
They are simply duping customers, which is highly unacceptable.
Below is the case reference number[protected]
shams.[protected]@gmail.com