Hello,
Sorry to hear you are having issues. Do know that the price does change according to your Geographic location where the tax rates are different on each location (States or Country). Perhaps it is best to raise support ticket using the link below, use the"Ask a Question" option. Include all information details. Such as price offered and price charged etc.

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