We got our coupons last week and our trip is 17 days out. If you are under 20 days, then yes I would call. If you are over 30 days, then I would not panic just yet. Keep checking the mailbox. But then again calling is pretty easy.
Back in 2010 you got a coupon for free 30 minutes if you rent a Sea Racer for 1 hour. Now it is only 10% off. The value of the coupons seems to keep declining.