If you are experiencing an issue with the Surface Pro (not relating to applications installed on it) i.e. the touch screen is not working, first you try resetting your Surface Pro see Restoring Your Device to Factory Settings for further instructions. If you try this and it doesn't resolve your issue, they you could phone Microsoft support for further assistance (NOTE: they will ask you if you have performed a restore to factory settings before helping with any other solutions)
To contact Microsoft phone 0344 800 2400