DSC-S500 Problem

Well, i'm from Chile (south america) and i bought the Sony DCS-S500 a week ago
everything was perfect, i took shots and some videos
but one day (well, 2 days ago) i turn the camera on and the camera turned off
i though it was the batteries, but they were full charged
i was desesperated, i just try to turn it on, but it turn off inmediatly
so i was to riplay (where i bought it) and the 15 of january they are gonna give me back another DCS-S500
but my question is, what's wrong with this model?
i read other forums and other links, and im not the only one with this problem
can someone help me and tell me what's wrong with my camera?
Thank you