Write a letter to the Bank Manager requesting him/her to change the Mobile Number in your account.
I have recently changed my mobile number and would like to update the new number in my bank account. My old mobile number registered with the account is _____________ and my new mobile number is _____________.
I request you to kindly update the mobile number in your records and ensure that all future communication is sent to my new mobile number. I have attached a copy of my identity proof and the document with the new mobile number for your reference.
I hope you understand the urgency of the situation and provide me with the necessary assistance in this matter. I would be grateful if you could confirm the change of mobile number in my account through an email or a letter.
Thank you for your time and consideration.