Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hi Sue,
If you did not cancel the Microsoft 365 Family subscription before upgrading to the Premium version, what happens is, you are charged for a full new subscription, then, the remaining time on the Family subscription is converted on a percentage basis (78%) and added to the Premium subscription, this process is explained on this link.
Log into your Microsoft account on this link (https://account.microsoft.com/services/) and check if the expiry date indicates your Family subscription has been added to the Premium subscription.