I'm really sorry to hear this.
The best thing is to send Tesco Bank a 'Private Message' so this can be checked out and an appropriate response can be provided.
Click on this link Tesco-Bank then scroll down, on the left hand side click 'Send Private Message'.
Complete it, click 'Submit Message' and this will send your message securely and privately.
Please include your full name, date of birth and postcode along with which account you have and what details are you looking to update.
You will receive a reply to your private message, with the appropriate response.
Warm wishes, Caz @25H