Airtel — fraud conducted by airtel representative

Address:

New Delhi, Delhi, 110018

A fraud conducted by airtel representative. He collected online payment of rs. 4314 on 10/08/2018 against txn no.[protected] and caf no. Given which is already under use 11214847.
We exchanged our documents through whatsapp +91 [protected]
Till date no refund initiated despite of repeated request.

If caf number given is incorrect / already in use by mr. Jain how can i apply online refund…