How do I unlock my Apple Account to update my apps?

Whenever i try to update my apps from the app store it shows that your apple account has been locked for

security reason. To unlock it, you must verify your identity.

And i tap on unlock account again it shows, for a security reason your new device cannot be used to edit your account information yet. this waiting period helps protect your account.

To reset your password now,use your other apple devices. but i don't have my previous iphone as i have given to my sister and she has removed my apple account from that device, So how can i unlock my apple account? please help me i cannot do my job without updating my application it is very important to update. I will be waiting for positive response. Thank you.

[Re-Titled by Moderator]