Airtel — airtel prepaid disconnected without consent

My number [protected] was disconnected without my consent and reallocated to someone else.

When i asked for information, airtel refused to provide it.

I had paid for the number to be valid for more than 20 years, and there was balance in the number when it was disconnected.

Airtel is not providing information on this as well, and are also refusing to tell exact date of disconnection.

In order to file an official case, i need documents related to the same from airtel, and they are refusing to provide that as well.