Sometimes Vine items can be damaged or broken in shipping. If this happens, you have a choice to make. If the item was 0ETV and you feel you can still give a fair and accurate review of it, this is often the best route to take for preserving your account review stats. However, if you were charged an ETV for the damaged item, or the item is too damaged/broken for you to review properly, it's better to get it removed by customer service.
You can send a message to customer service, explain the issue and ask them to remove the product from your pending review list: Templates for Contacting Customer Service
In some very rare instances, customer service may be able to replace the item for you. However, item quantities enrolled in vine are very limited and more often than not a replacement is not available.
If you wish to have an item removed, DO NOT review it. Vine TOS indicates ETV cannot be removed for items that have been reviewed.