Hello @Marisa_M ,
I'm having some trouble recreating what you're describing using segmentations in your account. My segmentations in your account were reducing the number of contacts from the larger lists, so I think it'd be better for us to collect more specific examples of contacts that should be excluded, what lists are being used to setup the segment, etc.
Ultimately, it'd be easiest to call in so we can collect and test this information live with you. If you're unable to call in, then please respond to the automated @ mention email with: