IDBI Bank's reluctance to share email IDs of its branches/officials with its customers

I am a customer of three banks, all PSBs, including the SBI (in which I was once a Vishesh Customer in the prestigious Nungambakkam Branch (Chennai) too. My pension a/c is with the Central Bank, Udyog Bhavan branch (opened in 1987 when I went on deputation as Director (Finance), Steel Ministry) which has been extremely nice and responsive to me, with a most competent and helpful Manager (Shri SK Chaturvedi).
I had to open an a/c in the nearest neighbourhood branch of the IDBI Bank (being a civil servant, I never deal with a pvt sector bank) essentially for Demat purposes and also for the close proximity of the branch to my residence.
Despite my best efforts and repeated requests, I have been denied access to the email IDs of the CR Park Branch or its Manager or any officer like the Manager, Personal Banking/Demat div., if any, or the CMD/any GM/any officer (if any) dealing with grievances, etc. The mysterious refusal of the authorities to heed to the Hon'ble PM's repeated calls for transparency in governance and emphasis on his concept of Digital India and follow a policy of total secrecy in respect of the email contact addresses of the management and the branches is a very suggestive to a man who, as an officer of the IRS and as a senior officer in the Steel ministry or as a senior most Chief Commissioner of Income Tax/Director General of Income Tax (investigation)-till retirement in November, 2004-always welcomed taxpayers or any aggrieved person to directly approach me anytime and any day. This can be verified from my former officer working in my team as far back asx 1985 and the present CVC, a brilliant IRS officer, Shri KV Choudary too.
In this context of the IDBI's refusal to part with the email ID of even the manager of the particular (CR Park) branch, I would like to share an even more mysterious fact--for those members who are specialists in IT.
I have received a few emails from my branch (the aforesaid CR Park, New Delhi Br), but whenever I replied to the originating email ID, my mail has invariably bounced back with the remarks that the mail was rejected/could not be delivered or something like that. In other words, if my branch manager wants to mail me something, s/he can contact me but I can NEVER contact anyone in my secretive branch through any email ID--in this age of "transparency" and "Digital India"--so much so that, as has been my wont and practice right from my initial days in the IRS (1969 batch), I cannot greet the branch manager or the dealing Manager, PBD (if any) on New Year's day or Diwali, etc., for which I used to send greetings at my own cost to my valued assessees inter alia like Rajiv Gandhi, etc.
I just want to know from the FS, as an investigator of tax evasion cases for almost 35 years (next year-2019- is the 50th th year of the joining of our batch in the civil services !), as to this inexplicable reason for total secrecy on the part of IDBI management on the matter of parting with their email IDs when I am free to contact my SBI branch (most indecent though) or Central Bank (most exceptionally responsive and always helpful-both on email and on WhatsApp). I just want the FS too to unravel this mystery--whether I am allowed to access my branch or the CMD of IDBI Bank through email or not. At 74, I have the right to at least know its reasons.