If you no longer have access to the mobile phone or tablet, which you used to set up your 2FA, you will need to contact our support team on: (+44) 0203 858 7269
We'll then go through some some security questions with you and switch off the 2FA so that you are able to access your account.
Once you are able to access your account, you can set up 2FA again by going to My Account, My Details and scroll down to Two factor authentication and clicking enable. You can then follow the instructions to set it up on your new device.