TLDR:
He received five emails between 29th March 2023 and 12th July 2023 from BoB for re-kyc but he ignored them.
Upon additionally receiving a notice from the bank through the speed post on the same day (12th July 2023), he became a bit serious and did the re-kyc by visiting the branch in the next few days.
Still, he met with another email and final notice through the speed post from the bank on 17th August 2023 asking him to do the re-kyc. It elevated his BP levels.
He has emailed the bank after his calls to the branch were unanswered and then waited for the reply.