Bad Service and Warranty

I bought a Samsung Galaxy Active Watch 2 less than a year ago. I was happy with the watch until it suddenly one day did not want to charge anymore. I sent it in for diagnosis and repairs as it is still within warranty. The repair shop told me that the device has water damage and this is voided by Samsung's warranty. Samsung market the watch as:

"Galaxy Watch Active2 has a water resistance rating of 50 meters under the ISO standard 22810:2010. It is not suitable for diving or high-pressure water activities. If the device or your hands are wet, they must be dried thoroughly prior to handling."

If only ever shower with the watch and swam with it twice and followed water lock, cleaning and drying protocols ad the watch was a very expensive investment for me. How can a watch be marketed as water resistant and when it gets "water damage" within its warranty, my warranty is voided and I have to pay close to the price of the watch to fix it?

I phoned Samsung and they said it can only get water damage to to my negligence. I find that response very disappointing as they have no idea how I looked after my watch and the care I took. I simply cannot accept the fact that my warranty is voided for a product defect (marketed as water resistant). I was also not given the option to dispute the "voiding of my warranty".