Hi Mim, thank you for coming to the forum.
I'm sorry to hear about the trouble you're facing, I will be happy to assist in the best way I can.
Please login to your Microsoft account, go to Services and Subscription https://account.microsoft.com/services/?ref=SMC-Cancel and cancel the subscription. Turn Off the recurring billing so it won't renew automatically next cycle.
If you are unable to cancel the subscription from your end, you may reach out to Microsoft support via live chat they are the ones who are able to help you with your cancellation and refund request.
1. Please click this link: https://support.microsoft.com/contactus
2. Choose Microsoft office 365 > Get home support
3. Type Cancel Subscription
4. Scroll down and click on Contact Support, log in to your Microsoft account
5. Choose your product
6. Chat with a support agent in your web browser
All they need is to verify your account first so that they can check it on their end.
I hope this helps. If you require further information, then please don’t hesitate to get in contact. I will be more than happy to assist you further.
Kind Regards,
Myk