Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
If you followed the steps on this link to cancel the Microsoft 365 subscription, then you should receive a full refund, the refund may take 5 business days to be credited back to your account.
If you do not receive the refund within that time period, this forum is just a user to user forum, no-one here has any account access, you will need to contact Microsoft Support directly, try using this method to contact their support.
Go to this link: https://support.microsoft.com/contactus
Select Microsoft 365
Click 'Get Home Support'.
In the box provided, type billing.
Press Enter, then on the next page, scroll down and click 'Sign in to Contact Support'.
Navigate to Microsoft 365 and Office - Manage my Subscription.
Select the 'Chat with support agent in web browser' option