What the heck is wrong with those girls? I say good riddance to them. You don't need them in your wedding and if they act like that now can you imagine how they would be acting on your day? Honestly, I would be glad you had it out now rather then at your DW.
I know you must be devastated right now but you may have really dodged a bullet on this one. They should be ashamed of themselves for acting so rude! It's their loss, not yours.