Frontier promises nothing but as you saw they go over and above nothing when the situation warrants. I would write to Fromtier requesting your vouchers. The point of meal vouchers is to provide you with sustenance while you wait for a new flight. Since the situation has passed, i would expect they would offer you a Frontier flight voucher. I belive Frontier uses electronic meal vouchers these days so I'm surprised they wouldn't have sent you vouchers automatically when your flight was.canceled. That's how Spirit does it. Good luck.