Jioairfibre — Voice call not working

I have got a New jio Airfiber connection, and from frist day the voice call is not working.

I have raised the complaint to Jio on 28th Aug for the same, but Jio team is closing the request without resolving it.

Also I have dropped a mail to appellate.[protected]@jio.com but still no resolution.
As I am not getting the full-service, i have asked JIo to either fix the issue or deactivate the connection with refund but they and not accepting my request saying that they wont refund the amount.
Fiber Connection number [protected]