S5 cracked

I own two Samsung S5 mobile phones. The one has a crack on the right bottom corner of the screen and the other ones screen is shattered when it fell. Both phones are still in perfect working order. I took the phones to the MTN dealer at the Mafikeng Mall for the phones to be sent to Samsung for repairs as they are still under guarantee. When the consultant at the shop removed the battery he informed me that the phones are water damaged and that i will be charged a fee of R350-00 per phone to get them back. When i inquired how can they be water damaged as the phones are in good working condition, i was told that the white sticker under the battery has turned red. When i asked him how is it that Samsung is advertising the phone as waterproof he informed me that Samsung is false advertising, the phones are not waterproof, then he told me that the white sticker could have turned red just by been touched by a moist or wet finger. But Samsung will still charge me R350-00 per phone just because the sticker has turned red although they are not water damaged. So many different stories. I need assistance from Samsung please. All i want is the screens fixed the phones are working perfectly.