Quick and free of costs:
This problem is caused by the build up of dust in the USB socket. Consequently the plug can no longer be inserted properly.
In order to avoid short circuiting during the procedure remove the battery. Take a needle and pick out all dust and dirt form the USB socket. Keep going, you'll be amazed by how much will come out.
Once cleaning is done you can reinstall the battery.
Plug will go in like never before ;-)