Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hey there, Stevie Hastie
Unfortunately, you are not notified if the trial subscription is about to be renewed. Instead, I always recommend turning off auto renewal after the free trial has been added, to ensure you are not charged. You can always turn this back on when it comes to renew if you wish to continue using Microsoft 365. When you have turned off auto renewal, you are notified when the subscription is about to end as it asks you to either redeem a new code or turn on auto renew.
If you have redeemed the personal subscription, you won't be able to cancel the subscription and get a refund. Instead, what should have happened is the subscription should have stacked. So you should see you have your month subscription and the 12 month subscription added together (showing it will expire in 13 months time) when you sign into the subscription management page here: https://account.microsoft.com/services/microsoft365/details#billing
The date will be shown under manage subscription.
I feel that if you tried to cancel the subscription, you would loose your 1 year subscription too. Instead, if you had cancelled the subscription first, before redeeming the 12 month sub, it may have offered a refund. You can try reaching out to Microsoft support to see if they can adjust something on their side and offer a refund. They can be contacted through this link: https://support.microsoft.com/contactUs
Hope this helps,
Nathan