LEGAL NOTICE ON PAYMENT OF THE UNUSED SERVICE

Sir/Madam,
I would hereby like to get a help from NCH on the broadband connection i have took from Reliance Telecom. As mentioned on the website of Reliance communication, the broadband internet plans are completely based on Advanced payment, which they call advance rental.
( http://www.rcom.co.in/Rcom/personal/internet/wired_postpaidplans.html)
This rental is taken before the subscription of the month begins and if you won't pay, you will not get the internet service or your service will be blocked. But they never followed that, On 21st February, 2016 my internet stopped working (the payment of the month is done in advanced), the customer care replies to the problem were unsatisfactory and completely disengaging from the solution. I made a complaint with the complaint number- 243275640. I was satisfied that there is a complaint, but this course never ended even after a week. At the same time, I received a mail regarding the payment. If i would have paid i would got internet service again for next month, but as the present situation of the broadband service in my area i never wanted to use reliance again. Therefore after two complaint IDs 243275640 and 243310746, I applied for disconnection before 4th March and got the two separate disconnection request for broadband and landline which are,
1. 243656087
2. 243656100

In the whole scenario, my internet service was broken from 21st Feb, and I would like to bring it in your notice that they follow the advance payment system, which means If i want to use Internet in February, I have to make a payment in January. As the month of February was till 29th and Internet got suspended on 21st, I had a loss of complete 8 days, but i let it go and was convinced with disconnection. I got acknowledge of termination request on 10th March and they have accepted my request of service disconnection.
The problem rose when I again received a mail regarding bill payment on 12th March. The whole thing of disconnection happened and the system was working on advance payment mode, why i need to pay for something I'm not going to use. Calling on customer care, they said after generation of bill you have to pay. If some XYZ company generate a bill on my name, that doesn't mean i'm liable to pay that. They have started sending legal notices asking for payment of the service I haven't even used. This is required to be stopped. When I inquired, reliance has done this to many people. If they follow an advance payment system, they already have taken my money for my service. So, I request to please look into the matter and help me answer the legal notice. Sir/Madam, it's not about the money, it's about the policy we have to follow and authenticity for transparency in the system.
And your system is showing upload failure with the screen shots.
Please reply soon.
Thank you.