Gear S3 (Water Damage) even though it is water proof?

I received my Samsung Gear S3 with my Vodacom upgrade. the yer warranty has passed and not long there after the watch could not go on. I have taken it into the repair store and they informed me it is beyond economical repair due to water damage. I have the report that I received and I was informed that this is a manufacturing default on Samsung's part. Now I am sitting with a watch that was meant to be used during activities but I cant get it repaired. The product is water resistant. How is it that an IP68 product can even be damaged by water? this has to be a manufacturing fault.