I have a pair of Nike dry fit running tights, which I wore a few times, and were great. BUT, the other day, the zip broke at the ankle. I was given a freephone number to contact Nike, but they told me to take it back to the shop I bought them from. I did that, and they wouldn't exchange them without a receipt. Unfortunately I shredded the receipt after I knew they fitted, and my credit card bill arrived. Surely if the goods are faulty I ought to be able to get a replacement. Can anyone help?!?