Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello
Is it because your macOS version is lower than version 12?
If so, if the subscription was purchased from MIcrosoft directly, 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 "Microsoft 365" > "Manage my subscription". You’ll then see the option to chat with a Microsoft support agent who has access to your account to help review the issue.
If you need detail step by step with screenshot, you can reference what I posted here: https://learn.microsoft.com/en-us/answers/questions/5931417/100-gigs-of-cloud-storage?page=1&orderby=Helpful&comment=answer-12846509&translated=false#newest-answer-comment:~:text=When%20you%20go%20to%20this%20page%2C%20you%20want%20to%20sign%20in%2C%20then%20click%20on%20Ms365
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If the purchase was made via Apple Store on your macOS, you need to request it from Apple, not Microsoft, because the payment processed via Apple.
Microsoft explains it here:
Apple's refund request instruction is here: https://support.apple.com/118223