I recently bought a pair of training pants at Migros Wetzikon, washed them at 30 degrees and wore them as pyjama pants. The next day I noticed little black balls of wool all over the house, and at first I didn't know where they had come from. It was only when this happened again the next day that I realized they had come from the tracksuit bottoms. I then checked the washing machine and the laundry and found the little things everywhere. My question: is this a reason for exchange, even though the trousers have been washed and worn and I no longer have the receipt? They are very comfortable in themselves and exactly what I was looking for, but if the lining (something 'teddy-like') disintegrates like this, I can no longer use them.