Why haven't I received new Crew Styles for my Fortnite Crew Pack?

After receiving a Crew Pack that is eligible for Crew Styles, you’ll unlock a Crew Style for every month you’re an Active Fortnite Crew subscriber. This starts the month after the Crew Pack has been received, and continues until you’ve unlocked all the available Styles (each Style will be added to your account around the 00:00 UTC on the 1st of every month).

You can check out the current Fortnite Crew cosmetics along with some frequently asked questions on the Fortnite web post: Unlock New Looks with Fortnite Crew Styles! (Opens in a new tab)