Brand new iphone 5s not working?

I got an iphone 5s in november. And it was working fine until about 2 months ago and it broke for no reason atall just stopped charging. I did get accused that it was water damage but it wasn't. So i got a new phone with insurance. (brand new) after 4 days it done the same thing. Its been like 3 weeks since that happened. I keep telling my mum to phone the insurance company but she never does it. I'm trying my hardest to get it to work. Any tips? I've been charging it for ages. I even charged it all night. I've tried 4 chargers in it… Has this ever happened to you? Anything will be great help.

Take it back?

Press the on/off button and the other button on the front at the same time. This should reset the phone.

Maybe you should phone the insurance company and explain that you iPhone, or is it a Nissan, is kaputt.

There's a great answer. As we all know you can't run a business at 14 (as you were 2 months ago) so sell the rights to your time machine to apple and I'm sure they'll provide you with a new phone.
Of course they don't guess the water damage thing. There's an indicator inside which changes when it gets wet. So your phone got wet whether you did it or someone else.

Apparently there's this trick that makes phones start working in that situation. Take the battery out, dunk it in warm water for about 2 minutes, place in a bowl of unboiled rice, and voila!