Moving this discussion to the Adobe Creative Cloud forum.
Brodie86 my apologies we faced some difficulties with our payment systems due to the scheduled maintenance. You should be able to place your order now. You can find more details at Creative Cloud Maintenance Scheduled for this Weekend | Adobe Customer Care Team.
Thanks Jeff for the reply.
I would have thought if there was scheduled maintenance it would be a good idea to temporarily take down the sign up page or at least provide some sort of warning or notification on the page to deter people from trying to sign up during this time.
The page says 'do not click back or reload the page to avoid duplicating your purchase'. I'll try again as you have suggested. Could you please check that my purchase wasn't duplicated?