the real question is did you order the pizza in advance? like the day before or 2 to 4 hours ahead of time?
if you did, then $25. is fine. had you called and said you were going to order 17 pizzas and you want a deal, they would have likely given you the coupon price anyway.
if you ordered 17 pizza's the day you needed them and expected them delivered in 45 minutes, then you should have not used coupons at all, and spoke to a manager and give you a one deal price that included tip....so the entire pizza staff got a benefit from the deal.