Hathway Cable & Datacom — harassment with sending legal notice

Address:	560036
Website:	www.hathway.com/Broadband

I was a customer of hathway broadband before 2.5 years and i raised a request for closing my account as i was shifting to a different place. I got email from them with a ticket no for disconnection. After even disconnection of my account for a while i started receiving invoice for paying the monthly rental. I contacted customer care and nodal officer and they confirmed these are system generated emails and asked me to ignore them. After some months, automatically, they stopped to send bill emails. Now suddenly after 2.5 years they sent me sms last month saying that a legal notice is generated for not paying rs.3800. I contacted the nodal officer again and someone called from them. They again said no need to pay the amount. Again today they sent the same sms. I have all the evidence with me in email that my disconnection happened on so and so date and a confirmation from their end that no need to pay anything. But why are they harassing me again and again. Can someone from legal department help me how to file a case against them for harassing me? Enough is enough and i want justice now. Please help.