In my country and most probably in the OP's, no one gives a fuck about customer service. And they don't accept returns either after a few days from purchase. What's even worse is that since Nintendo doesn't have an official presence here, there's no warranty for the hardware.
OP's only hope is to find an experienced hardware person and follow an online guide to disassembling the 3DS.
Damn! Thats the same problem I have right now! If I was in the US, I would send it to nintendo right away!