Hello
Mistake happens, You can explain it to billing support and they usually would understand and help you process the refund.
This is a public forum, so for your privacy and security, we can’t help with billing issues here. Also, no one in this forum has access to your account or payment information.
To get help, open the "Get Help" app on your computer (just search for it in the Start menu). or go to https://support.microsoft.com/contactus, Type "Billing" and press Enter. On the next screen, click "Contact support" at the bottom of the page, then choose "Windows" > "Manage my subscription." You’ll then see the option to chat with a Microsoft support agent.
You can reference this detail step by step instruction with screenshots I posted in this thread: https://learn.microsoft.com/en-us/answers/c/2714817