Bharat Sanchar Nigam [BSNL] — not refunding security amount

Address:

Sirsa, Haryana, 01666

My landline phone number was,[protected]. It was disconnected in apr 2017. But my security is not refunded till now.
Amount 4100/-approx.in this regard i visiting sirsa office and account officer (Lady) mailed to higher authorities. But after disconnecting phone ten months no response given by bsnl. While other customers who were disconnected their telephone after me, they have received their security from bsnl.
Why my security is not refunding..
Rakesh kumar garg
15/155/4, bansal colony, backside vaishno devi mandir, sirsa
Mobile no [protected]