I have unexpected restart

The only way to mark data as being valuable is with backups.

Otherwise, our important data is one drop, dunk, corruption, loss, theft, fire, etc., away from loss.

Unfortunately, too many of us learn this lesson by losing our data, too.

You will have to find copies made prior to the loss.

With the “was not working properly” problem, and the reset, there is no data on the device.

What you were told is correct: a reset clobbers everything on the iPhone.

Maii8989 wrote:

How to reset clobber everything on my iphone , i have try many in website but its not working , all my photo that i lose i no have sync with ICloud , 😭😭😭

Reset permanently erases everything, yes.

Including deleting all photos not in iCloud, not backed up, and not copied elsewhere.

A reset permanently erases all data.

Recovery of photos from a reset device requires having a device backup (a backup that would have included photos), or use of iCloud Photos, or copies of the photos shared or transferred elsewhere, and any that must have happened prior to the reset.

As explained in the terms of use you agreed to when you signed up, you’re not talking to Apple here. The people responding are Apple users like yourself. That's what this forum is - users reaching out for assistance, assistance being given by other Apple users.

I would bring your phone to an Apple Store or Apple Approved Service centre.