I am Vinod. I will try my best to help you resolve this issue.
What I understand is your ipod always works in the shuffle mode, correct? Is that something which developed recently OR is it behaving the same from the day you bought it?
Anyway, let's try turning off the shuffle. Start by playing a track. Now, on the screen, you can find buttons for forward, back, pause etc. Slide from right to left until you see a screen with three icons - repeat, genius and shuffle. Tap on the shuffle icon.
Let me know whether that resolves your issue.