iPhone 4 unable to charge

I've had an iPhone 4 for nearly 2 years now, and have never had any problems with it. However, I was away on holidays recently and noticed that my iPhone kept saying "Charging is not supported with this accessory" whenever I tried to charge it using the provided charger that has always worked. I also tried other chargers, different sockets as well as an in-car charger I have, but they all gave the same message. The only time the phone charged was when it was turned off and plugged in, but that took much longer than normal.

Now its gotten to the point where my phone has no battery at all, and simply won't charge. I've put it in recovery mode, and attempted to restore on iTunes, where I got a variety of error messages. After about 10 tries, I finally got the iPhone to restore, and I got a message from iTunes saying that the restore was successful and that the iPhone will appear in the window, which it never did. I've restored it a few more times and I'm still getting the same problem, as the phone won't charge at all, iTunes will not detect it.

Is there anything that might work that I havent already tried? Or am I going to have to take it to an Apple Store, the reason I'm in no rush for that is because my nearest store is over 80 miles away.

Thanks for the help.