Another Surpass Statement Credit Question

Ok I recently got the Surpass card. And I already used it, and I got my first $50 statement credit. Now I thought it was just that. A credit for my billing statement. Like my monthly Amex statement balance is say $500. But they gave me a credit of $50. So I only owe $450. But then I just got an email telling me “Use your $50 statement

credits by June 30.” How do I “use” my credit if it’s already applied to my balance? Sorry if this is obvious.