Bharat Sanchar Nigam [BSNL] — landline security deposit not received so far

Address:

Flat no 202, Sesha sai Apts Bagh Amberpet Hyderabad, 500013

Security deposit for my land line no:[protected] not received so far even after lapse of several months.. When i requested again they sent a message as show. Below.

Dear customer, your landline bill for rs.-1987/- against billing account number [protected] & phone no [protected] has been generated on 01-oct-2019. Pay by date is 13-nov-2019. To view bill, click: https://mybillview.bsnl.co.in/DL_SZ/webresources/app/htmlformat?ke=2110201916060...⇄ please ignore if already paid.

So kindly send me the security deposit amount soon