not disconnecting my connection after making several requests

Location/place: Kolkata

Name of company/service: reliance communications pvt Ltd

I have a reliance post paid connection in delhi. But since I got transfered to kolkata in my current job I didn’t get time to disconnect my connection manually. But I had called up in the customer care several times n requested them to disconnect my connection but they are not doing it. And I have to pay the bill every month.