Hi @Josh Thomas ,
Typically you can find hidden or self-service subscriptions in the Microsoft 365 admin center under Billing > Your Products. After you cancel the subscription, refresh and delete, you may need to wait 24 hours before it reflects properly and you can delete the tenant.
If you tried this already and cannot find any subscriptions in the admin center, I would recommend creating a free support ticket with Billing and Subscription support so that they can delete these manually and get this resolved.
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