Iphone 4s won't charge unless it's turned off?

For the past couple of months or so my iphone has stopped charging unless it is turned off. Also, when I connect it to my laptop itunes doesn't recognise it, nor does it charge. I have tried changing chargers and cords as well as the usb port, I have also tried to reset it and have deleted all content on it but nothing seems to work. It's no longer covered by warranty either so any suggestions would be very much appreciated.

That's really strange. Is your phone under warranty at all? I'd contact Apple and see what they suggest but the phone should charge. How long have you had the phone?