The Branch Manager,
My name is _________ (name) and I write this email in reference to the bank account that I have been operating for the last ______ (duration). My bank account number is ________ (account number).
Through this email, I would like to bring to your kind consideration that I am facing issues with the Internet banking facility that is being provided by your bank. I am facing problem like ___________ (mention your issue).
It is to request you to kindly help me with it and get the same fixed at the earliest as this is causing inconvenience to me.
Thankful as always,
____________ (Contact details)