How to recover a hacked Telegram account on iPhone and unlock it?

Fraud, cheating because friends hacked telegrams wrote to go to the account and not a friend wrote, the young man went to the account and blocked his phone unknown people writes that the iPhone is lost and that's it, changed all the passwords, what to do in this case and whether it is possible to do anything about it and somehow write to support to unlock it ??????

[Re-Titled by Moderator]

Original Title: Fraud