Does it by any chance have a reset button?
Its a bit stupid if you have to wait for the battery to go if its not removable.
If it does, try pressing that to reset the player.
If this doesn't work, I'm afraid you'd have to wait for the battery to go if nothing else works.
If the problem carries on to continue, since you have a 1 year warrenty, send it back and get a new one
That is all I can suggest