Problem after the cortana upgrade installation_Lumia 520

After the recent cortana upgradation of my Lumia 520, anothe4r notification to install one missed file appeared seeking permission. After that installation, within one day my phone went wrong, refreshing continuously with out leaving any time space for any operation. And the phone could not get charged. I can not opt factory settings since the phone is not responding to any of my touch operations.

soft reset the phone: press the volume down and power button at the same time, hold until you feel a vibration, then let both go.

Report back if that helped, if not we'll go for a hard reset