I wanted to change my gamertag. Online it says I can change my gamertag "once for free". I have had a gold account for like 8 years, and never changed my account. My gamertag was initially made offline, and then I started paying for gold under the same tag, it never was changed. When I go to change the gamertag it says "You can change it once for free." but when I go to "Claim it!" it wants to charge my card. Can I have some help?