craftgrrl | NEED HELP on snaps!

Hi everyone, I was wondering if someone had used these type of snaps before. I'm on a deadline (friend's bday tonight) and I thought I fixed them, but I'm still having problems with the snaps. I have the appropriate attacher tool and I've been hammering like crazy, but I can't get the backing to stick to their fronts. I'm not sure if that made sense.

Ok so my problem is the snaps won't close because. The individual halfs won't stay together! So each side of the snap you see has two pieces.

you're supposed to put B over A and then using this little attacher tool (that looks chizel like) hammer that until that nose on A widens so that B can't unattach from A. So these two pieces make half of a snap thing. So my problem is after hammering the thing like crazy, it stills doesn't stay together. Please help!

Also I just realized. My bag is knitted and possibly can't handle the force of this jacket made snap when opening them. >.< . I already lined the bag with polyester too. Any ideas of how can I reenforce the knitting piece?

incase this might help here is the rest of the bag.