Airtel — Not able to disconnect despite repeated attempts

I have an airtel black plan, which was put under safe custody. I tried to get the service activated, but the company didn't activate my plan again. Then I tried to deactivate the service, and they are not deactivating either. I have been to the airtel store, tried to call the customer care, and did everything in my power. But they are not deactivating at all. My bill is getting accumulated, when I am not even using their services. My dth number is [protected]-001 and wifi number is [protected]_wifi