The name that displays on your listing pages is your Username, not your Store Title.
To change your Username:
- Go to your user account found here.
- From the Account Summary Page click Account Settings under the Settings section of the left hand navigation.
- From the Account Settings page, change the Username field to your desired username.
- Click "Save" at the bottom of the page.
To make sure your account is branded properly, it is best to also update your Store Title if you change the username so they match. This will allow customers to easily identify who they are purchasing from.