My iphone 4s doesn't charge at all. Via wall adapter, or usb regardless of cable). Always shows plug icon, never the lightning bolt.

My iphone 4s worked perfectly fine for 1 year. Then all of a sudden one day it quit charging. It does show the plug icon (regardless of how charged it is), but the battery percentage number keeps dropping. It drained completely and I took it to get repaired. They changed the battery, which gave me one more day. (long enough to back up my pictures and take a few screenshots showing this plug icon regardless of charge level.

I have tried 3 different cables, and have tried to charge my phone on two different computers. No results. I reset back to factory settings/ installed the newest system update. Still no results.

Please help.