How do I fix the touchscreen in my Audi A1?

My touchscreen in my Audi A1 has suddenly stopped responding, how can I troubleshoot and fix this issue?

First, try resetting the screen by simultaneously pressing and holding the power button and volume button until the screen goes black. If that doesn't work, try disconnecting the car battery for a few minutes and then reconnecting it. If these troubleshooting steps don't work, it may be a hardware issue that requires a visit to a dealership for repair.