On your transaction page on top right you can see 3 vertical menu options dots in that you can find raise dispute option, although just to clarify it only works if the transaction is new or less than 48hrs, older than that you need to raise a dispute...

It has been merged into samsung wallet in One UI 6 itself please check in the wallet once

Obviosuly Please go to the service center they have a back glass kit which helps retain the water resistance if by any chance after fixing the issue it comes back they will fix it again for free, I got my S20 FE same issue got it fixed, outside might...

You can raise a dispute on it, I did get a response on quite few transactions lot of times

Oh my god 25th hmmmm