If you have redeemed a purchased XBOX card on your Microsoft account and noticed that funds have been reduced without any purchases or orders made, it may have occurred due to various reasons:

• Non-utilization of the balance on your account for a period exceeding 25 months.
• Potential problems with the key.
• Other issues with your Microsoft account, such as a violation of their terms of service. 

Should the issue be related to your key, we kindly request you to contact us via the Resolution Center. However, if you have reason to believe that the issue is not related to your key but to your Microsoft account, we recommend reaching out to Microsoft Support directly for further assistance.

Check how to contact us through the Resolution Center by reading this article.