Airtel — Airtel extreme fibre broadband

I registered for airtel broadband on 27th April and the installation team told me they would install the connection on the same day and asked me to make payment. 3 days after making advance payment they are telling me that the connection line does not exist and are not responding on my request for cancellation. I'm escalating this issue here and if I don't receive a proper response soon I will reach out to consumer court for such malpractices.