You probably missed those VIP expiration notifications. They appeared 10 and 3 days before the deadline and also in the latest update we added 2 more notifications, so now VIP Managers get notifications 30, 10, 3 and 1 day before expiration moment.
In comparison to all other Managers, VIP Managers currently receive Notifications when the training session is ready and sponsorship expired. In future, there will be some more VIP notifications.
VIP can be renewed or extended using DS Diamonds.
Menu - Community - VIP features (Extend VIP)