I know my ID and password, but it keeps asking me the same security question and I don't remember the answer to it. Then after so many attempts, it locks my account for 24 hours. And I didn't set an alternate e-mail. So how am I suppose to do this?
The Yahoo website relies on the security questions to recover the password in case you forget your password. If you don't know the answer(s) to the security question, then account recovery is not possible and it will never be possible. You actually need to remember the answers or you'll lose your account forever.