I had the same issue. I cancelled our accounts, sold all the stock i own in Spotify, and notified my friends who work at Spotify to RUN RUN RUN for the doors. Spotify cancelled our account after apparently sending an email, emails that went in most cases to spam or old email addresses in my daughters case. They demanded some address verification, which were happy to do. But, meanwhile, 100% of my family was using the app, almost EVERY DAY, and had they simply put up a screen that says "ANSWER THIS QUESTION OR WE CANCEL YOUR ACCOUNT" then i'm sure we would have done it. When i logged in, our address was in the account. But, look, if you need a user to do something, ask them when they're in your app. don't send emails with an 8 day timelines and cancel when no one reads emails, right? But the reason I cancelled, sold my stock, and notified my friends to RUN away was because only the worst run company would terminate their users by email THEN, this is the kicker, not allow you to fix the problem. That's the kicker. RUN. If you have a spotify account, RUN AWAY NOW. Only the worst run companies in the world terminate subscribers then REFUSE TO LET THEM RE-JOIN.
I told them when they asked that I would need $500 to re-join, because an idiotic company like Spotify (which it's now apparently become) will waste at least $500 of my time per year. So, we're now an Apple Music Family. Yes, we lost 7 years of playlists. We lost all of the shared playlists. But, you can't make up this level of incompetence.
I can promise you, this would NEVER happen with Apple and for that reason, we're now an Apple Music Family. If you have run into the same issue, I'd recommend you take the pain of rebuilding playlists and start over... it's only going to get worse from here.