This gift exchange is pure BS. For some merchants, the captcha would show up, it'd recognize the balance and all that (giving you a glimmer of hope), only to fail at the last screen after you 'Accept' (ther will be a loading icon that'd just keep spinning all the time).
And the customer support is non-existent. I emailed to no-avail. I called and got hung up on after some 30 mins of back and forth.