Hello,
Sorry to hear you are having issues. But, not clear on your issue. Your issue is not able to purchase ioniq Windowblinds skin due to you Creadit card being rejected. Or, You cannot install Windowblinds 11? Please clarify.

Thanks
Basj,
Stardock Community Assistant.

Hello,
Sorry to hear you are having issues. Please raise support ticket using the link below. 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.

https://stardock.atlassian.net/servicedesk/customer/portal/4/group/13

Thanks
Basj,
Stardock Community Assistant

Hello again, 

Have you raised support ticket? If you did, can you post your support ticket number.

Thanks,

Basj,
Stardock Community Assistant

Not really sure what you mean, I am responding to you and trying to help you.

Thank you,

Basj,
Stardock Community Assistant