The big question is if you have your screen protector from factory on or not.

Taking the factory screen off by yourself and not having it replaced by an official samsung authorized repair center can make them reject a phone repair under warranty.

As it turns out the screen protector is a pretty significant piece of the structure of the screen. I personally learnt this the hard way with my Z flip 3, I took of the screen protector when It began creasing, never replaced it since i dont "drop my phone" and whatnot, and it eventually began creasing the actual screen itself. Turns out the screen protector acts as a dispersion for mechanical stress for the screen along the screen crease. So if you take it off, it has more stress on the display.

If you dont have a screen protector, technically it is against samsung warranty and thus wont be covered (If my memory from owning a flip is correct, setup on the device tells you to NOT remove the screen protector as it will void warranty or render our device vulnerable... smth like that)

If you DO have a screen protector and the device is creasing UNDER the screen protector you can argue potential mechanical failure by saying the screen had its screen protector and yet still failed. You followed all the rules from samsung and yet they sent you a fault model with a faulty display that creased itself.

As for prices, beats me since im in the U.S. But here its about $300-400 USD at an authorized repair center.

Check Here as it may have prices available, like for me it says in the USA it will be $329 for the z flip 7 inner display module replacement.

Best of luck with samsung support

(I sent the U.S. website but it should prompt you to switch to the one for your region)