[williamting]

If username does not exist, have you created one? If not, create one using the email address you use for registering your purchase to avoid confusion. If the email address you first use for your purchase, is no longer used, you can use a new email address but be mindful that correspondences will still go to the now non existence email. So, you have to check manually for any response to your support ticket.
Quickly go to log a ticket. I am sure that the people at helpdesk are fast provided you provide all the purchase info, problem, etc.