Hello.
In general, whether the license is legit or not, it is not legal to sell a product as one thing when it is actually another. This falls under deceptive advertising and could be considered fraud. A few red flags here - Windows 7 license can no longer be used to activate Windows 10 or 11. There are indeed Windows 11 license keys.
You can file a complaint with a consumer protection agency in your country. For example, in the U.S., you might report it to the Federal Trade Commission.
In addition, you can also report to Microsoft via this form: https://www.microsoft.com/en-us/howtotell/cfr/report.aspx?rtc=1