Go shop at the store, get to the checkout, have them do the checkout, and when they refuse to bag it, demand an immediate refund. The policy will change in a very short time, and much much more effective than boycotting, as managers see instantly what the company policy is costing them in manhours to restock shelves from abandoned purchases when they won't pony up a little bag.
Get enough doing it, the policy gets changed. I do this whenever I go to the Republic of Pasadena. Someone will tell me that the law says something, and I say - don't care, you want my business, you'll bag those purchases, or you can get a manager over to do the refund right now. Yes, it is a jackass thing to do, but they let this law go into effect, they didn't fight it, and they can deal with the fallout. Total number of times a store has actually refunded my purchase? Zero. Every time, they magically find bags to put my purchase in and away I go. And it never fails that someone behind me pulls the same thing.
We'll try that.
Someone will tell me that the law says something
Thing is...the law in HI does not outlaw paper bags, only plastic. Yet Target is not supplying paper bags either.
The checkout girl tried to tell me that paper was outlawed also. It's a lie. Every other store in town is supplying paper.