Hello Naaman Poingsett,
I'm sorry to hear that your Starfinder Core Rulebook's binding is coming undone. Usually, we ask that books purchased form a third party seller are replaced through that seller. As this item is a gift, it sounds like that will be quite difficult to achieve. If you can please send a picture of the defect to customer.service@paizo.com, and we can work on getting a replacement for the book sent to you. Thank you!