I've never experienced that, personally, so didn't think of it. I just say "no" and that's the end of it every time.

So, if you want to work for change, the first thing you need to do is to stop spending money in those stores. Every dollar spent at a business is a vote encouraging them to keep doing whatever they're doing.

The second thing to do is to let corporate know you're not shopping there and why.

Those things won't have a huge effect unless lots of people do them, but they'll have a much greater effect than harassing the poor front-line workers.