Get wal mart to accept veteran discounts

I was in our local wal mart with my grandfather today an he handed the lady his veteran discount card to the cashier like he does every where else.. An the cashier went and got a manger which then continue to explain that they do not do veteran discounts an even seemed to have a problem that he even tried ... An asked what am I supposed to do with this .. Then handed the card back to him an went and talked to someone else who once again said they can't do that ..
I have been in the same wal mart an others an seen them give people on welfare and ebt cards discounts ... Now if they can't do it for people who severs this country but will for those who either choose to not work and live off people who do or they can't honestly work then why can't they do that for our veterans.. So am askin for everyone who think and believes that they should to sign this to get them their discounts that they worked for and deserve ...