Reliance Communications — NBt billing

I have given net connection in month of septomber & after two net not working properly I in form the reliance officer but he donot give any positive reponce , I told him dissconet the connection after that he dissconet the connection . after one month later i have given the net bill. I complaint the custmer care but donot give any positive reponce .untill now I receive more than 5 monthly bill.what can I do pls give me suggetion.