Bad Service- Repairs for my account

Samsung S5 screen damaged when phone fell. Samsung repaired the screen free of charge as per contract agreement. 5 days after the phone came back a glass of water spilled on the phone. Now there is water damage to the screen and motherboard. This should not happen because the phone is suppose to be water resistant up to 10m. The repairs are now charged to my account. This is unacceptable, the phone was not repaired properly and does not live up to it's specs