Gamertag can’t change

On xbox it says “You’ve used your free gamertag change. To change it again, you’ll need to buy a gamertag change on xbox.com.” I’ve never changed it and it doesn’t tell me i need to buy a gamertag change when i try on xbox.com, it just does nothing when
i click claim then gives me the error when I refresh.

Was your gamertag an auto generated gamertag, that the system gave you when creating your account, or did you pick one from the suggested list below the auto generated one? If you selected from the suggested list, or entered your own on creating your account,
this is classed as using your first free change. All changes after that are paid changes.

You can of course use the new system that is rolling out https://social.xbox.com/en-us/changegamertag This is a new system and will allow a free change. You can pick
any gamertag you want and if it is already used a #number is added after as an identifier.

Have you tried changing your ganertag using your xbox instead of using the internet too see if it works for you that way?

i checked on my xbox app, and it looks like no one has it, and usually it would tell you and just add numbers at the end

Probably the gamertag is taken maybe that might be a reason of the issue