Is it possible to file a formal complaint against a bank for refusing to accept deed poll?

My bank kept nagging me about re-uploading my identity documents and of course they changed my name back to my deadname. I changed my name with them years ago and had to do it several times because they kept reverting it. Now they say that their policy changed and they no longer allow deed polls without a supporting form of ID. I don't have a UK passport, my country doesn't allow name changes to the other gender, and i applied for a provisional license but haven't heard back in a long time so idk if im ever getting it. Honestly ive spent an hour crying and feeling suicidal because it feels like such a setback. I can't make any payments to my therapist and tutors because nobody in my life knows my deadname. Im currently trying to open an account with a different bank and hoping they will accept deed poll. Is it possible to make a complaint about my bank and make them change my name back? Im 19 and an immigrant so idk how shit works