This is something that has been debated in the vine community and no one have a solid answer.
On the vine portal, inside vine help you have this information:
Does Vine offer returns?
Amazon Vine items are not returnable or replaceable but may be cancelled.
But, if you go inside your regular Amazon orders page you will find "Return or replace items" option and the automated system will allow you to return your vine order in exchange for a new one.
Many users have been using this option to replace broken vine products and it is unclear if someone have been punished for doing so. Just do not abuse the system or you will might be flagged by the regular Amazon system like any other customer.