Do I have to invite someone I have sent a save the date to?

We sent out our save the dates months ago and I sent some to some old school friends of mine as when we see each other we always have a great time, it just doesn’t happen often. Since then, they’ve been really terrible friends. Really snide and sneaky behind my back but so subtle about it like leaving me out of whole group meet ups. I’ve confronted them and they’ve either ignored me totally or made up lame excuses. They’re coming to the day part of my hen (this in itself should have warned me, they’re the only ones not coming for the whole weekend) it’s getting worse now and getting to the point where I need to start thinking about sending invites so my question is this: am I obligated to send them an invite since they got a save the date and they’re coming to my hen and if so, is there anything to say it can’t just be an evening invite? I don’t really want people at my wedding at all who go behind my back in the way they have, especially since there are people I’ve left off the list in order to invite them. Any thoughts greatly appreciated x