Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
1
If you paid Microsoft directly for your Microsoft 365 subscription, sign in to your Microsoft 365 subscription at this link.
https://account.microsoft.com/services/
Select your subscription and click Manage, you can then cancel the subscription from there and also ensure you disable recurring billing on the subscription.
You should be entitled to a prorated refund, and you can check your refund eligibility using the steps in this link.
2
If you paid for the subscription through the Apple App Store, you need to contact Apple Support to cancel the subscription and receive a refund.