Hi,
Can you confirm if the subscription is reflected in the Microsoft account used for the purchase?
https://account.microsoft.com/services
Does it show as active?
If yes, when did you purchase it? Please note that it can take up to 48 hours for the update to reflect across all services.
Also, please confirm if the storage has already been applied by visiting: https://outlook.live.com/ Go to Settings > Accounts > Storage, then expand both the Microsoft Storage and Cloud Storage sections.
If the storage is still not updated, I suggest contacting Microsoft Support directly so they can check this for you:
Click this link: https://support.microsoft.com/contactus/
Sign in to your Microsoft account
Select Microsoft 365 > click Get home support
Type “Chat with an agent” in the text field and press Enter
Click Contact support at the bottom
Select the product you need help with
Follow the prompts to connect with a live agent or request a call back.