Why is not my phone responding properly after updating to 8.1?

[WPCentral Question]

My lumia 620 has got a touch screen problem after updating to 8.1.When i try to turn on my phone,the screen does not respond and i cannot enter my pin code.So i have to remove the battery and put it back in order to restart my device.The problem occurs once a month but this week i experienced the problem twice.Thank you...