Bharat Sanchar Nigam [BSNL] — Generating bill for 5 months even after disconnection of landline

Dear Concerned,
On march 14th 2022 i personally visited BSNL office situated in TK layout Mysore, and gave a written letter signed by Officer to concerned department with counter signed for acceptance for disconnection of my landline with immediate effect and refund back the deposited amount, after which again every month bill is getting generated, to enquire the same i visited the Office where they said to contact Mr. sathya keerthi who was unavailable in the office so explained him my concern in call and he assured to rectify immediately, but still its not rectified and bill is getting generated even after 5months of disconnection, and if i am call Mr. sathya keerthi he is not picking the call and customer care portal says they cannot take this complaint, and people in BSNL office say to speak to GM Lingaraju, when i called him his PA picks the call and same drama of putting blame on others, but no one is ready to solve the problem, till today remain same,
request the concerned peoples to please take proper action and refund the deposit

Landline no :[protected]

Thanks and regard
Vikram