Airtel — applied for broadband connection. airtel fail to install the connection and hasn't refunded the money

Address:

Pune, Maharashtra, 411014

I applied for a new airtel broadband connection on 30th may 2017. They were fail to connect the broadband service because of some technical issues. I paid 500 rupees as advance payment for the connection through online payment mode. There was no response from airtel for the refund after writing them on facebook about the issue on 8th june 2017 they replied on 10th june 2017 saying we have tried calling you but there was no response. Anyhow after few days i received a text from airtel saying we have issued the check (I paid online on their website. (Why in the world you'll refund me in check. To add inconvenience to the customer) and tracking details were there. I message them on facebook again on 23rd june that i still haven't received the check. Airtel replied saying the take 7-15 working days for customer to receive the check. On 6th july i told them its been 21days and i still haven't got the check. Then again they tried calling and apparently my phone was switched off.
I told them to try calling again (When you have to tell this to a company then you know it they have really pathetic customer service) they called on 24th july and the senior executive asked me to call the courier company (Why i have to?) but i anyways did because its my money and i care about it clearly the don't. I tried calling them immediately after airtel's call and it wasn't going through so i wrote back to ariel about it on 24th july 2017. They replied back on 26th saying my number was not reachable.