why won't my ipod turn off properly?

For several months now, whenever I hold down the play button to turn off my iPod, it'll start back up again. Even once I switch on the Hold switch, it'll light back up, but be completely unresponsive. When I switch on the Hold, the iPod will make the clicking sound that it makes when turning on several times and the screen will flicker. It sometimes takes up to six attempts to get it to turn off and stay off. I've already attempted holding down the center and play buttons to reset everything, but it doesn't work at all. What does it mean and what should I do?