Change account phone number

Hello, 2 days ago i lost my phone and naw i want to connect my yahoo mail and it say that i never login in on this new PC ..and want to send me a verification number on my old phone number .. i tried many things from Yahoo suport , and says *The Password Helper says my password can't be reset online

If you get a message saying that you can't reset your password online "for security purposes," you'll need to contact us to regain access to your account. * i tried to find where i can contact them but nothing. ( i know my Mail : name and password and the number that i lost )
If anyone can help me .:D Thank You !