Here is how to contact Microsoft directly for complaints and warranty purposes:

-First search in the browser Microsoft Contact Us or you can clickhere

-Then select Surface Device, Get Home Support

--Then type: Talk To Agent

-After that, click Sign in to contact Support

-If you have signed in and can log in using your Microsoft account

-There will be options for live chat and call back. After that you can submit your requirements and don't forget to prepare information/evidence regarding the unit you own :)