Well I just noticed that the wall plug I was using was from my iPad and is a higher current supply (2.1A). The iPod Classic won't take a charge from that one, but an iPad and an iPhone will.
The Samsung charger I was using us 5V 0.7A and would not charge it. However, I have a no name charger that's 5V 1.0A and it works. Strange but I guess they're picky..... Problem solved.