Marital Status Discrimination

I consider myself a pretty happy person. I have a great group of friends and family that loves me, but there are times when it seems like the world rubs my singleness in my face. There have been times when I almost feel discriminated against. I recently was at a large chain bookstore, when after being super frustrated with the sales woman in the children’s department not knowing anything about child’s lit, I went to the counter to pay for my other purchases when I handed over my debt and membership cards. The cashier informed me that my membership (discount) card had expired, and that I could renew it for $25. When I declined she kept pushing the membership, trying to sell it on its merits. The more I said no, the more points she made. Finally she said to me, in a very perky voice, “but your whole family can use the membership.” For me this was slap in the face. Was she assuming, that because the norm of culture is to be in traditional family by my age, that I am. So very firmly I responded, “I’m a family of one thank you.” Took my card back and left the shop, leaving my purchases on the counter.
My question is this, if a store or organization is including families (4-5 people) in the cost of their memberships, shouldn’t there be a discount for those of us who are families of one? Or Should we be finding ways to redefine the family?