have you or have you not tried the oven technique?
Also, If the sensor is still white, and the ipod is under warranty then get your ass in that apple store and demand they replace it. Tell them that they are legally obligated to make any repairs if it is due to manufacturer defect. If that doesn't work, demand to speak to the manager. He will surely give in. Throw in that you were planning on buying an iphone and even a macbook pro (it just sounds good) and how you heard that apple had great customer service, but now you are rethinking because of 'this horrendous experience.' If you are truly in the right, and you start to make a scene, they will replace it. Its customer service 101. The customer is always right. always. This, of course, is not the most tactful approach to the matter, but if you feel they are stiffing you then it is worth a shot.