[Resolved]  BSNL Coin Box — not returning back deposit

I stopped Coin box PCO of Bsnl before 6 months. I gave application to disconnect my BSNL connection, i gave an application to disconnect my connection, their no due amount on me of bills and i wrote in application to payback my deposit to me.
But still they are sending me bills and not returning back my deposit. the worst customer service across the nation. still they will not improve there CUSTOMER SERVICE, a day will come when their is no Customer to them.
Wish them good luck.