Mahanagar Telephone Nigam [MTNL] — Refund of security deposit for surrender of landline

Address:

Malad

I have surrendered our telephone number[protected] with the instrument for which I had applied for refund of the deposit amount and extra charges levied on us by the company for extra 3-4 months.
The date of surrender is 21st april 2021 which is more than a year. But still we have not received any refund amount for the same.
Hereby I am attaching the photos regarding the surrender form and complaint letter of the same.
I Request you to look into the matter and do the needful at the earliest.