Charging problem

So...in the past 24 hrs, my iphone 3gs hasn't been recognizing when its plugged into the wall charger or computer. I took it to the AT&T store and they tested it and it didn't work either, so I know that its the phone, not my cord or charger.

I have a feeling that there may be something wrong with the part that the cord plugs into, as before the battery died (from not being able to be plugged in), there were no software issue...

WHAT CAN I DO????

Going to an apple store is not an option, as the nearest one is 7 hours away.