If they won't honor the price for when you need to schedule, then just tell them you'll go elsewhere (just like the age old bluff with cable companies). But yeah call corporate and complain. A "box" lasik place like them with many facilities nationwide should give you the discount regardless. Check with your insurance, while not covered most vision plans will have some type of discount provisions for lasik if you go to a place they are signed up with.
FYI to all those who are talking about necessity for glasses later on, it is true that sometime the eyes will still get worse again over time. I'm on the 10 year mark now and have 20/20 with no deterioration (although I could get a small script if I wanted better than 20/20). Reading glasses are another thing. Lasik fixes the curvature of your eye, it does not fix the muscle weakness which occurs with age which is the main reason why a lot of people with or without the surgery need reading glasses as they get older.