Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
The process to upgrade from one version of Microsoft 365 to a version with more features is provided on the link below.
If you did not cancel the Family subscription first to get a refund, when you upgrade to a version of Microsoft 365 with more features, you are charged for a full new subscription, then the remaining time on the previous subscription is converted to the new subscription on a pro-rate percentage basis (in this case 78%) and added to the new subscription.
Log into your Microsoft account on this link and check the expiry date on your subscription to ensure the subscriptions have been added together.