iPhone 6

If the steps in the article below don’t work, contact Apple ID Support, although I’m not sure they will be able to help. 

Apple ID - If you forgot the answers to your Apple ID security questions

From the article below. 

Without proof of your identity via security questions and other carefully selected criteria, Apple Support can't help you reset a password or perform any other actions on your account. These policies are audited and reviewed on a regular basis.

Security and your Apple ID

Apple ID Support

Apple ID Support (2) 

Apple Support by e-mail or chat    Work through the screens to get a chat option. 

Apple Support using Twitter

Or fill out and submit this form.          The form is for iTunes, but it will get passed to the ID Support section.  

Обратитесь в службу поддержки Apple ID, используя указанные выше ссылки.

Попробуйте форму. Вы проверяли русский контактный номер?