Just want to confirm we are on the same page. Turning it off - meaning - pressing both the POWER button + the VOLUME UP button didn't work?
Supposing you have attempted (volume up + power button) a hundred times then I will not ask you to try it again... then it's about time to contemplate getting a professional help. In case you decide against it see below steps:
You're gonna need a USB recovery drive (installer) to reset windows but you'll lose all your files (unless you've back them up) and a product key of course...
To reset your Surface from a USB recovery drive:
1. Make sure your Surface is turned off and plugged in.
2. Insert the USB recovery drive into the USB port.
3. Press and hold the volume-down button while you press and release the power button on your Surface. When the Surface logo appears, release the volume button.
4. When prompted, tap or click the language and keyboard layout you want.
5. Tap or click Troubleshoot > Reset your PC.
6. If prompted for a recovery key, tap or click Skip this drive at the bottom of the screen.
7. Tap or click the target operating system you want to reset. This refers to the current operating system you have installed on your Surface.
8. Tap or click Yes, repartition the drives. On the next page, tap or click Next.
9. Choose either Just remove my files or Fully clean the drive. The option to clean the drive is more secure but takes much longer.
10. Tap or click Reset. Your Surface restarts and the Surface logo appears while the reset process continues. This can take several minutes.
11. Surface Pro 2 only: During the recovery, if you see the American Megatrends screen, press the Esc key. If the Surface UEFI screen opens, tap or click Save & Exit.
If Windows starts: Install the latest Surface and Windows updates to help prevent future problems. For more info, see Install Surface and Windows updates.
12 if this doesnt work, get it serviced.
source: https://support.microsoft.com/en-us/help...