Telkom dissapointment

I took out a cellphone contract beginning October at Telkom the grove mall, used the phone for 2 weeks and then i put the phone away until early February,when I decided to use the phone again The screen didnt respond when ever touched and took it back to Telkom as its still under warranty and i was told i need to pay R4800 for repairs as warranty was voided due to water damage and i refused to pay and i was told that i need to pay R198 to get the phone back,when I asked whats the 198 for the lady said assesment fee which was never disclosed to me..So now I keep asking myself where did the phone get water from because clearly it was not on my end..