DO NOT FLATTEN THEM OUT. Doing so will blow the sides of the magwell out at the corners.
You can cut them out and they will work in any standard AICS pattern bottom metal or chassis. Depending on your setup though, rounds may push forward in the mag and catch on the action.
You’d be much better off returning/exchanging them if you can, or selling them and purchasing the correct mags. You’ll lose a few bucks most likely but it’s better than butchering a mag and having to toss it in the trash and buying the right ones anyway.