Why my coby mpc833 won't work

i got my coby to turn on finally with a new battery and finally got it to work but the only way it would download songs was by connecting the cord to the mp3 and the computer because it wouldn't work by putting the mp3 directly into the port. it let me download my songs and it let me listen to them for a while but then the next day it would play but it wouldn't advance to another song i would have to manually forward it to get it to play. the next day even with changing the battery again, it won't play at all. you can here a little bit of static sound but thats it and thats only when you can get it to stay on. and now when i plug it in either way it won't register on the computer like that usb drive doesn't exist. i've also tried a different computer. HELP!!! I've been shafted. i cant get music on my cody mp3