Personally, I would contact them and see what they're willing to do. If you have to fix it yourself, you can. But it may require investing in a snap setting tool. Usually snaps consist of four parts. Two for the female side and two for the male side. There is a little "iron" or "jig" that you have to set them into and hammer them with a pressing tool to get them clamped on either side of the material. It's easy to do, and I've done thousands of them on leather goods, but if you don't have the tools it's not going to work well.

I'm sure that clothing manufacturers probably have fancy machines that do this instead of doing it by hand, but the process is still roughly the same.

When the male side stuck to the female side, did the metal break away from where it was? Or does it look like it just wasn't set (pressed) tight enough with the other backing piece?