How is this discrimination?

I was reading this article on ripoffreport.com and this person states that they are being discriminated against because the company they went to refused to accept their gastric byp surgery card. WTF? I work at an all you can restaurant and we used to take those cards and give those people discounts. That was until they started eating 10+ plates. Now, no one can get discounts from those cards. But how is that discrimination?