Here is where I had a problem..
My screen stopped to...
I called T-mobile and they explained to me that the phone was still under warranty and they would swap it out...no charge...
(except the little notes like "water damages etc.." would cause the warranty to fail-$100, but it wasnt)
so I sent it back...and they sent me the new one...
A month later...I had a $130 charge on my bill...
I called them and asked them why..
they told me I voided the warranty because of water damage.
Now its an ongoing battle to have the charge removed...