If you purchased additional storage for your OneDrive, it will show up in OneDrive but may not reflect in your local system storage settings. OneDrive storage is separate from your local disk storage on your computer. If you want to see the additional storage reflected in your system, ensure that you are checking the correct storage settings for your local drives, not just the OneDrive settings.
If you are still unable to see the additional storage or if it seems like it is not applied correctly, you may want to check your OneDrive settings or contact support for assistance. Your purchase was not wasted, but rather it may require some adjustments to view correctly on your system.