SC Delete Not Deleting Service
sc in PowerShell is Set-Content; so if you are running in PowerShell, you likely have a file called 'delete' with your service's name as its content
If this is indeed your issue, use
sc.exe delete servicename
Service can be marked for deletion, but may not be deleted immediately, since something holds it. See this answer for possible holders: https://stackoverflow.com/a/20565337/1943849
In my case, I just closed the Computer Management window
Make sure to stop the service first then run the sc delete command. It will take care of closing any running process.