If you haven't yet done so, click Information regarding the upgrade to check if there is something you overlooked.

You might need to go to https://www.vegascreativesoftware.info/us/support/interview/ and on the opening page click (I need help with) Order/Delivery/Payment. After a few clicks you should be able to describe your issue and proceed to send a support request.

If that seems too complicated, just try emailing infoservice@magix.net with your pre-sales question.