Why did you put your valuable phone in a product with out testing it first? would have taken 5 mins to stick a sheet of paper in it then shove it in the sink, you can't really expect them to reimburse you.
Lifeproof cases are very good but even they say to test their product before relying on it and can't be held responsible for damaged phones, else everyone who dropped their phone down the bog would go out and buy a Lifeproof case and claimed it leaked.
I have few of these in various sizes on the boat...
Karrimor | Karrimor Dry Bag | Outdoor Equipment
An emergency one with first aid kit, travel towel etc, we use one for day to day stuff and also great to put the wet stuff in on the way back from the beach, I know they work as they are a bugger to get the air out of.