Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello,
Did you previously have a Microsoft Office 365 Personal or Family subscription and then upgraded to a Premium subscription?
If so, your Personal or Family subscription would have been upgraded to the Premium subscription. The remaining days on your previous subscription would have been converted at the applicable rate and added to the Premium subscription. Therefore, if you cancel it, your entire Office 365 subscription will be canceled.
So, if you want Pro, you can purchase the Microsoft 365 Pro edition using the same Microsoft account. The remaining days on your Premium subscription will be added to the 365 Pro subscription.
See,
How many days will be added to a Microsoft 365 subscription upgrade?
If you are proceeding with the refund process, I recommend contacting Microsoft Accounts & Billing Support using the link below*.*
- Go to this page: https://support.microsoft.com/en-us/home/contact
- Type Talk to an agent then click Get Help.
- At the bottom of the page click Contact Support. Sign in to your Microsoft account if needed.
- Select Other Products then Billing and Account Profile questions then Confirm.
- Click Chat with a support agent in your web browser.
Let me know if you still need more help.