Hi @arianna316, welcome to the community!
Sometimes the information once given to Spotify (regarding the users’ addresses) don’t match the ones they have. The data might be incorrect, incomplete or outdated, hence the removal of some users.
In this case I suggest you get in touch with the Spotify Cares staff - They'll be happy to help you further with this.
There are a few ways to contact them.
Another great way is to reach Spotify via Facebook support. Shoot them a message here: Spotify Cares.
When you message them, inform all the e-mail addresses on the plan.
Let me know if this helps!
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Note: I'm not a Spotify employee.