Recently several of my fave stores have released coupon policies, so I figured I'd link up a few for ya. I usually don't have any troubles at my fairly coupon-friendly stores. If you, however, are one of the unlucky ones that gets those jealous-of-your-couponing-skills cashiers, then I'd suggest printing these out and taking them with you to prevent future incident.Then you can politely pull it out and point out the policies to inexperienced or un-knowledgable cashiers. I would not, however, suggest arguing with anyone. It's not worth it to #1- Give yourself an "oh-that's-the-horrible-coupon-chick/dude" reputation and more importantly #2- it's never worth it to lose your cool and testimony.
RiteAid- Coupon Acceptance Policy
Walgreens- Coupon Policy
Target- Coupon Policy