Press and hold the for about 10–15 seconds until the screen goes black. If the phone is frozen and won't turn off, remove the back cover (if removable) and take out the battery. Wait 10 seconds and put the battery back in. Note: If your Itel A48 TOP has a sealed battery, hold the Power button for 20 seconds to force a shutdown.
Use the Volume Down button to scroll down to Wipe data/factory reset . how to hard reset itel a48 top