If touch doesn't work on your Surface, your touchscreen most likely experienced a hardware failure. There are several possible fixes for this:
Option 1: Replace the Touch Screen
If replacing the touch screen is the only option, you can learn more about available parts and replacements here. You'll need to disassemble your Surface and remove the digitizer panel and LCD screen. Then, you can buy a new touchscreen or have a third party repair it.
Option 2: Reset Your Surface Touchscreen
If resetting your touchscreen is an option, follow these steps: