Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
To request a refund, you need to be able to sign in with the Microsoft account associated with the old email at https://account.microsoft.com/services, locate the subscription, select Manage > Cancel subscription, and follow the refund prompts. As mentioned here: https://support.microsoft.com/account-billing/how-to-get-a-refund-on-a-microsoft-subscription-67dca30b-b323-44d5-acc2-e02f9902c472