There are a few things that can be causing your purchase not to go through. Below is a list of things you can try to resolve the issue and attempt to complete your purchase.
In case you are using Google Chrome go to "Settings", Search for "Cookies", go to "All Cookies and Site Data", search for "JVZoo" cookies and delete them.
For all other browsers a helpful alternative is to clear your cookies in general.
A good free tool to do this is CCleaner http://www.piriform.com/download.
You can clear your browser cache or use a different web browser.
This process will assure that you have cleared any affiliates who may have been cookied in the previous attempts.
If you are making the purchase through an affiliate link try the direct sales page link once you have cleared your browser. If it is unknown to your JVZoo support can be contacted to help you locate it.
If you are still unable to purchase, the seller may be having trouble with their payment processor. You can try emailing the seller for further information.