Two-step verification process is the best way to safeguard your account from the unusual and hacking activity. After enabling two-step verification you have to enter a unique code along with password every time at the time of login. If you don’t receive the code even after enabling two-step verification then it’s high time to interact with customer care via Yahoo customer support number 1-844-794-2515 which stays put 24 hours a day. They have the tools and techniques to troubleshoot your issue in a fraction of seconds.
Visit here:
http://www.customer-service-tollfree.com/support-for-yahoo-email/