My iphone has water damage?

i got my iphone 4 through at&t, summer of 2010. it was great, until june of 2011, i dropped my iphone into the toilet and it wouldn't turn on from water damage. i took it to the apple store and explained my situation, and the guy that was helping me was nice enough to replace a new iphone 4 for me for free. he said this was a one time thing and i signed my name underneath a contract saying so. i was so happy he was so nice to give me a free one, i took real good care of it. until yesterday i had dropped my phone into the sink. it won't turn on, again, it's damaged.
does anyone know if i take it to apple again, they'll replace this one for free? (doubt it)
or if i have to buy a new one for $299 or if they'll charge me for a full retail price of $649??
please help. i want to know what i am walking into when i go to the apple store.



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water damage iphone