Did you get the offer by email?
Its possible that you will get a bill credit offsetting the cost.
Check your next bill.
It is so dumb the way Fios does this. They send you a promo via snail mail and you just have to take a leap of faith that they will reimburse you later. If you call customer service they have no idea what you are talking about. haha Its just crazy
Did you have the option to choose reward as a payment?
If so, that is the way to get the free movie.