Update All info from YEARS ago, new cell#

I am tech-challenged. 70 with some memory probs.
Info from years ago needs updating,cell # change. I also need to update security question. Would be willing to give landline # for a one-time use. I don't understand why Yahoo doesn't allow one to simply e-mail for help. I have spent 1 hour of my energy trying. I did change my password, however, that would not help if I cannot update info with new question and cell #. To update,I am unable to provide old info of when I opened account.Please help,dont just brush me off with some 'help" link.