You will need to factory reset it and start over.
Press and hold both Volume down button as well as power button until the screen goes completely black.
Once it is black release the power button only. Do not release the volume down button.
You will be booted into the bootloader mode.
From here you can select recovery mode by navigating using the volume up or down. Use power button to make a selection.
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion.
This is not Customer Service so we are unable to help with account specific issues.Currently using:
Pixel 7a (O2 & Lyca), One Plus 6 (Sfr), iPhone 12 Pro Max (Vodafone)