Quoting David Fitzgerald,
My ticket has been closed after sending the requested images, apparently you had not had a response from my within two days (strange as the time between your support emails is ALOT longer than 48 hours...).
This same issue has happened to numerous people who have posted on the boards.
I've now no option but to contact trading standards over the matter.
edit: I've been requested for a rough scale of the issue so all those who are having the same problem, please do send a PM over to me so I can get a rough idea of the number of people with the same issue of a new copy of the game being "invalid" and the lack of support from SD.
The ticket was closed due to an unfortunate quirk with our support system. When there are large attachments on emails, our support system reroutes the email in order to avoid clogging up the support servers. Sometimes, the ticket doesn't get updated properly, which ends up triggering the auto-response that tells you that the ticket will be closed, and then if we don't receive a response, the ticket is automatically closed. Check your email, there should be something there for you.
Stardock doesn't just ignore people. If you get a message that we're going to close your ticket, and the situation isn't resolved, please contact us, as there may have been a problem with either your or our response. You're also welcome to join our IRC chatroom, or send a PM to a mod through the forums and they can get in contact with us to make sure nothing has gone wrong. We have set up numerous avenues to get help just for these types of situations.
Also, there are many reasons why people get the 'invalid' error, including, but not limited to, initially registering the serial number to an email address that is no longer in use, misspelling their email address when initially registering the serial number, or being sold a used copy under the guise of a new copy.