My iPhone 4s won't charge! I've tried everything?

I have an iPhone 4s and until about 5 days ago it was working fine, then when I went to charge it, it wouldn't charge. I assumed my charger had messed up so I got a new one, that night, it charged, but then the next day I had the same problem with that charger! I did some research and people said to clean it out because there might be lint, I did. That didn't work. Then I saw that my battery might be too old and I should replace it. So I bought a new battery & watched some how to videos and I put my new battery in. But now it STILL won't charge, AND it restarts every 5 minutes?! I know I put the battery in right. Is there another way to fix this? Or should I just throw it away and buy a new phone?

Mine did this, I asked a repair man, he said to me, bang the phone on your knee or a hard surface with abit of force on THE LEFT HAND SIDE. It really worked for me! Try this, if not take your phone to a repair shop to see what's up

It sounds like a battery problem.it isn't holding charge/not charging. It will reboot when on itunes as your pc doesn't supply enough output to charge battery while it is trying to send information to the computer.supply is less than demand. Swap your battery and then re evaluate.