I followed the instructions on the website and there was an ommision which meant when the .less file is accessed, I got this error
Error Summary
HTTP Error 404.3 - Not Found
The page you are requesting cannot be served because of the extension configuration. If the page is a script, add a handler. If the file should be downloaded, add a MIME map.
The final thing you need to you in your web config file .less files to work is to add entry in
system.webServer/Handlers
This omission on the website had me stumped for a while.