Hi I have the Asics Gel challenger 8's. On the page it doesn't state anywhere that it has the 6 month guarantee, but a few people in the comments say "good thing it has 6 month guarantee". So could someone let me know if there is a guarantee. Also I didn't buy them from TW, but from ***** sporting goods, so if I send it in to Asics will they give me new shoes? Oh and do they let you get credit towards other shoes? say Gel Res 4's? Thanks!