You might also find your answer in the LastPass Enterprise Manual.
How do I refund a purchase for Enterprise licenses?
Refunds can be processed up to 30 days after purchase. To refund your purchase do the following:
- Log into the LastPass account that made the purchase
- Click on the LastPass Icon > Tools > Advanced Tools > My Account or use this direct link https://lastpass.com/my.php
- Click 'View Receipt'
- Click 'Cancel' next to the purchase you would like to refund