a lot will depend on the place you bought the paint from and the person that you talk to from here on out. Sears and other major retailers will ask you to bring in samples of the flakes for their review and you will get the results in 2-3 weeks which will be that there is nothing wrong with the paint. They may or may not offer to replace the paint but I have never understood why I would want to replace problem paint with more problem paint.
The "Big Box" stores may offer to replace the paint--but probably not. This is why their prices are cheaper.
I suggest that you take more samples and the empty paint cans, if possible, to a friendly local paint store and ask when the grumpy old man or woman that really knows paint will be in. Seems like all the best paint stores have these. He/She will tell you that the Behr paint is bad (or words to that effect) and that you will have to scrape and sand it off.
If your contractor bought the paint, still follow the last suggestion. It will help if you can get some real direction from a pro who has seen more of the problem than we can. He probably knows who the good and who the not so good operators are in your area also, so do listen carefully to what HE has to say. He will choose his words so plan to read between the lines as well as listen to what he has to say. If you get confused on the reading, he may clarify a little--but probably not much--so listen carefully.