Airtel Digital Tv - Delay in refund of amount

I received this mail from the Airtel.
This is with reference to your request towards refund of Airtel DigitalTV ID **********. As per our telephonic conversation with you on dated **/**/****, we would like to inform that your complaint about disconnection has been registered with service request number ********. Our team is working on your complaint and will update you with the status by **/**/**** (**:** PM). We would like to inform you that all customer premise equipment/s (CPE) is the sole property of Airtel. It needs to be returned to the company at the time of surrendering the connection. Please note that we don’t charge any security amount and also the initial payment made is towards the installation/activation and for subscription of the packages (depending upon the offers opted for). The only amount refunded is the available balance on your account if it exceeds Rs.***.
We regret the inconvenience caused to you and look forward to a long and fruitful association with you. Please note that your reference No is ********** for any further correspondence.
Still, now I am not getting my amount refunded. Request your good self to refund my outstanding amount of Rs.*** /- immediately without any delay. This is second mail which I have to send to Airtel for your reference:

Dear Sir,
As per your email, I have not received any response from your side for a refund and today I had a discussion with your service executive and service team lead assured that tomorrow you will get the call from Airtel for refund confirmation and further process. Expect your response tomorrow for a refund of money wide S.R.No.******** /**.**.****.