Hello,
Sorry to hear you are having issues. I believe you have 2 issues here. Account issue and activation issue.
First, lets look at the activation issue. Need to be clear, you're trying to activate Start10 or Start11 on your system? If you trying to activate Start11 with Start10 keys, it will not work. But, if you're trying to activate Start10 with Start10 license key it should work without issue, unless you have a typo in the Email address area.
If the second is your issue, please raise support ticket using the link below, use the Ask Question" option. Include all information details. Remember to record down the ticket number for future reference if needed. Do not raise multiple ticket, that will make your ticket back to the end of the line. Send once and wait. Ticket will be answer by the order they send in.
Also, please include your "Sorry, you do not qualify for upgrade pricing at this time." question in there.
https://stardock.atlassian.net/servicedesk/customer/portal/4/group/13
Thanks
Basj,
Stardock Community Assistant.