BSNL:mobile - Assam — unpaid dues

Sir,
I had taken a connection in 2004 from Tezpur BSNL. This number was surrendered in )ct 2005. Last week- Sept-2008. I received a letter from the Chief accounts Officer speaking about unpaid dues. I seriously dont understand why it took the organisation so long to send me such a letter- if ever there was such a problem. Contacting the concerned person on is desk is impossible and he is never free for an appointment. Mails have been sent but there has been no response from the Assam circle. Delhi has deigned to reply saying that they are looking into the matter. But the letter from the Office - Assam BSNL threatening "Legal action" gives me only 7 days. I am in a quandry as to how to proceed. How can a named organisation like BSNL harrass the common people like this?