Rejection of UTR application

Good morning, I've been trying several times to apply to get the UTR number, but I keep receiving rejections because the address does not match HMRC records. For some reason, I'm not able to verify my identity to access my personal tax account and change the address, therefore I called the helpline and asked to update it. Even after that, I keep receiving rejections for the same reason. Could you kindly provide advice on how I could solve this issue? Thank you

Hi sissi05,
If you've been having issues applying for a UTR, we can help with your application. 
Please contact us by webchat or phone here:
Self Assessment: general enquiries
If you're still experiencing issues registering for a Personal Tax Account after you've updated your address, contact our online Services Helpdesk directly.
You can reach them here:
Technical support with HMRC online services
Thank you.