Bsnl-bharat Sanchar Nigam Limited - My sim card not active by bsnl

I have a postpaid sim of bsnl ********** ..Then I close my postpaid sim and converted in prepaid sim to same number..And bsnl ballia office where I submitted all my documents regarding this sim ..And they said your sim will active in * to * days ..Now already passed ** days but my sim card not active ..And I really required that no ..When I call in bsnl office initially they attend my call and say Ur sim will active in few days but many days passed and now no body attend my call ..I really harash by this bsnl office .. I have also text so many massage that person who sitting on that table where all sim activate by office .That is only I have prove that person no is ********** I only want to active my sim .So kindly solve my problem..