Bill of Rs 2000 for Zero Internet service

Location/place: New Delhi

Name of company/service: TATA teleservices ltd.

I was using Tata Photon Plus with a monthly plan of Rs. 750 which promises a speed of upto 3.1 mbps and minimum of 256kbps.
In november 2011 i shifted to a new location and the misery with this device started.
Initially i was experiencing frequently disconnected service and speed of less than 100kbps and after some time it became a contious experience.
When i lodged a complaint with the company in month of JUNE they sent an engineer at my place to confirm that i was not lying and he convinced me that they will solve the problen in 4-5 days which never happened and after few more days when i enquired for the same on customer care i was told that the company doesn’t have a network in my locality and they can’t solve the problem.
Finally the company disconnected my account and they are asking me for bill of those 2 months where i never utilized the service at all.
I need help to sort this out.