Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
If you had a Microsoft 365 personal subscription, then upgraded to the Family version, what happens is the remaining time on the Personal subscription is converted to the Family subscription at a pro-rata percentage (92%) to extend the Family subscription, if you then cancel the Family subscription, that essentially cancels both subscriptions.
Did you receive a refund for the Family subscription after you cancelled it, and if so, was the refund just for the price of the second Family subscription, did that not include the personal subscription converted time.