[Resolved]  Reliance Infocom — Asking for Settlement

Almost 5 years back I returned my Reliance mobile phone to the company and paid off the balance due remaining and settled everything. After a year I got a letter stating that I need to pay Rs.2400 or will have to face the court. I called the customer service department and I told that everything has been settled previously and nothing is due from me. They told me that it was a mistake and I will not receive such letter in future. Recently, I mean after 4 years, I received a letter from Reliance Infocom stating that I need to settle the account and pay Rs.2400 as fee and Rs750 as advocate fee. I doubt I don't have the bill that I have settle almost 5 years back. Its really embarrassing. What shall I do in this regard?