Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
You are only entitled to a refund if you cancel the Microsoft 365 subscription.
When you upgrade a version of Microsoft 365 to a version with more features, like switching from the Personal version to the Family version, what happens is you pay for a new subscription to the Family version, then the remaining time on the Personal subscription is converted to the Family version on a pro-rata percentage basis, in this case 92%.
That process is explained in the 'Switch to a Microsoft 365 subscription with more features' section on this link.
Check the expiry date on your Microsoft 365 Family subscription to ensure that has happened to the expiry date on the new subscription.