Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Based on the message: "We can't cancel your subscription. You have already paid for your Business subscription. It will expire automatically on 11/6/2027", it appears that the subscription has already been paid for and is currently set to expire at the end of the subscription term rather than renew automatically. This may be why a cancellation option is not available in the subscription portal.
If you purchased Microsoft 365 Business Basic today and would like to request a refund, I recommend contacting Microsoft Support directly for a refund review. Refund eligibility depends on factors such as the purchase date, subscription status, and the applicable billing terms associated with the purchase.
As this is a public user-to-user support forum, community members do not have access to your subscription, billing details, or account information and cannot process cancellations or refunds directly.
I would recommend contacting Microsoft Subscription Support and requesting a refund review: https://support.microsoft.com/contactus
When contacting support, it may be helpful to provide the Microsoft account used for the purchase, the purchase date, and a brief explanation that the subscription was purchased using a personal Microsoft account and that you would like a refund review.
Microsoft Support will be able to review the subscription and advise what options may be available in your specific situation.
I hope this information helps.