My iPhone 4s won't charge?

On Thursday night at around 1am I had just finished charging my iPhone 4s and it was at 96%, I then unplugged it and left it like that and went to sleep. I woke up the next morning and it was at 1% so I charged it for 30mins before I went to school. When I went to unplug it from the charger it was still at 1%. My phone then died while I was at school but I tried charging it at school for almost 2 hours and it still would not charge, it stayed dead, and stayed at 1%.

I tried reseting it by pressing the home button and the sleep button at the same time but it did not work, the black screen with the empty battery sign just showed up intead of the Apple logo. When I came back home from school I tried charging it again at 11pm, and then I went to sleep. I woke up and it had finally turned on but it was still at 1%.

I've never dropped my phone (with all honesty), and I bought it 5 months ago.

A friend told me to try restoring it but I don't know if that will help. I have an appointment with the Genius Bar tomorrow, but I have been unable to use my phone for the past 2 days.

So is there a probem with my battery or is it my iPhone's hardware?

Please help!