Non refund of security deposit

Location/place: Howrah

Name of company/service: BSNL

Dear Sir/Madam,

I gave up my broad band connection on 24.01.2012 (W.O.No.33006677449). After so many follow-ups also, till not I get the security deposit amount(Rs.500/-)
My telephone no. is 033-26675534

Regards,
Anindya De