My support tickets were about 2 factor authentication which had stopped working. I am unable to do anything with my account.
A couple suggestions,
When it fails and you are asked to do the CAPTCHA, ... don't go back to the previous form and try again,
REALLY use the form with the CAPTCHA.
And another thing ... the timing seems to be really tight. Enter the CAPTCHA part first, then enter your OTP with plenty of time before it expires. If GLBSE's site is running slow, it seems to not process the login request right away and by the time it does, the OTP is then no longer valid. So you want to submit the form as soon as you've entered the OTP.
And yet one more thing. If the time on the device with Google Authenticator is wrong, the OTPs it generates will be invalid. Perhaps reboot the device and hopefully that will trigger the device to do a time synch that is more accurate.