@i.love.res > eating something is better than not eating. You can try mixing in a pellet of what you want the turtle to eat with what it's currently accepting. It may start eating both and then you can begin to introduce more and change your pellets over. If it hasn't been mentioned here already, it's definitely on the feeding part of this site. You can soak pellets in some tuna water to entice eating.
As far as picture posting... look at steve's post. He's got a how-to link in his signature.

