Hey Mel,
Welcome to the forum. As someone already pointed out, you can always ask. I don't think any of these promotions are set in stone. If they value your business and are afraid you'll leave if you don't get another six months, they just may accommodate you.
But if you like movies, I think there better ways to spend your money. Netflix <http://www.netflix.com> allows you unlimited DVD rentals for about $20 a month. Keep the movies as long as you want, send it back when you're ready, and they'll you the next one on your list. This way you can get just the movies you want. Best of all, no due dates or late fees to worry about.
