Dell Student Discount, false advertising

I recently purchased a Dell laptop under the student program. I received an email with a $100 coupon that is reads only valid for future purchases. I am now trying to use that discount to purchase something, and the website says that it has already been used. I haven't purchased anything and when I called customer service, they told me "that code is no longer valid because more than 25,000 people have used it already.". They also said there is nothing they can do about it. This should be considered false advertising as it says nothing about a 25,000 limit in fine print. After years of supporting Dell, I am fed up.