hi, my iPhone was hacked by scammers, it is blocked how to solve this problem?

Sadly this is a new common scheme.

Contact Apple Support directly with your purchase details of your device and they may be able to help you.

Contact - Official Apple Support

It's likely your account has already been compromised:

If you think your Apple ID has been compromised - Apple Support

How to use account recovery when you can’t reset your Apple ID password - Apple Support

Your post is a very good warning to others to not add an unknown person to your iCloud account. This is a common scam that allows them to block you out of your account simply by changing your password. You would not add an unknown person to your bank account, so do not add them to your iCloud account.

As for reclaiming your account, you can try to remove the Activation Lock by following this support article. You will be required to prove your identity and in most cases will need the original receipt for your device from Apple showing the serial number of the device.

How to remove Activation Lock - Apple Support

In addition you may be want to review this article, which also provides details on reclaiming your account.

If you think your Apple ID has been compromised - Apple Support

This is a nasty scheme. It happened to me approximately 10 days later. Thankfully I managed to unlock it with Apple Support by providing the receipt and the IMEI of my phone.