Consumer Redressal

I had taken an internet plan from Tata communications. And paid an advance of Rs. 5516/-. Installation was done but the connection was not activated. I was told by the executive that the billing will start from the date of activation. However, the service provider has charged from the date of installation. Now, they are alleging that I should pay them an amount of Rs. 2084/- for the unused period. I have asked them for the usage data. But they are not providing me the same. I have also sent you an email providing the details of my complaint. Kindly guide me through.