My iphone Lost mode lock got bypassed and theifs have Access to my informations

In addition to what Kurtosis12 has already said...

Please understand how Lost Mode lets you lock your iPhone, iPad, iPod touch, Mac or Apple Watch so that others cannot access your personal information.

...

Turn on Lost Mode or lock a device

• In Find Devices on iCloud.com, click All Devices, then select the device you want to put into Lost Mode or lock. ... 
• Click Lost Mode or Lock.

More items...

Use Lost Mode in Find Devices on iCloud.com - Apple Support

If you fell for a phishing scam there is nothing further you can do. The thief now owns all of your data and also Apple ID, unless they did not change the password. If they didn’t that’s something you should do right now→If you think your Apple ID has been compromised - Apple Support

Getting your Apple ID password phished when two-factor authentication is not enabled too often ends this way; in a data integrity and privacy catastrophe, and here unfortunately also combined with device loss.

Just as soon as that Apple ID password is compromised, then Find My, remote locking, remote wipe, everything is unavailable to you.

We can provide sympathy, and can provide pointers to (maybe) recover from a compromised Apple ID.

We can’t fix this.

Nobody can get back what you have lost here.

And yes, if the thief was inclined, everything here was copied, the stolen device permanently disassociated from your Apple ID, and whatever data associated with the compromised Apple ID was erased should the thief have wanted that.

At the thief’s option, the Apple ID can further be permanently deleted, bricking other associated devices, too.

Unfortunately, the two Apple recommended answer above are incorrect for this case, given the reported successful password phishing.

Don'ts

If the device is removed from an account after it is erased, Activation Lock will be turned off. This allows another person to turn on and use the device.

If the device is still under your Apple ID then no one can get into your devcie.

An example of my iPhone 5 is given in the GIF below. There is no "Undo" after you remove it from your account.

This is a user to user forum, no one here can delete the data on your phone.

What to do if your phone is stolen.

If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support

mourad116 wrote:

Thank you very much for your answer..

I had 2fa on and I also still have my apple account (I changed the password), it's just that find my is now deactivated and the phone still shows up on my apple account (my devices) by the way.

I was sent a link and i filled my information and my phone was automatically gone.

Is there a possibility for the thief to get access to my data? Or he has to factory reset it (delete all the data) so he can use it?

I regret to inform you that you’ll only have left what the thief was inclined to leave you with, and clearly you encountered a professional thief. Without going into details of exactly how, bypassing two-factor with access to both a trusted device and with the password is feasible. Once phished, there is nothing else to do.

Log out of your iCloud first to avoid your information and pictures been stolen or copy. Then change your password and secure your device

No, Apple does not get involved with stolen phones.

If the thiefs gain Access to my devise via Phishing. Will my data be erased?

That will depend on whether the thieves erase the phone, which they probably will so that it can be sold.