Unable to verify identity...

I have been trying to update my address and claim refund for my self-assessment account for months! I am able sign in using my Government Gateway ID but as soon as I try to update details or claim refund I am asked to verify my identity. I have tried using my passport, driving license and details of my last self-assessment claim but none of it works and the details I am entering are definitely correct. Digital assistant is of no help and I have been calling everyday for weeks but have so far been unable to speak to anyone. I‘m on hold for an hour at a time then the call drops and I have to ring up again. I am at my wits end. HELP!

Hi

If you have been unable to verify you will need to contact our Self Assessment team.

Self Assessment: general enquiries

Thank you.