norton locked screen when changed sim card

When i put in another sim card yesterday norton mobile locked my tablet and is asking for a passcode, but the problem is that there is no keyboard showing up so i can put in the passcode. So i got in touch with norton to and try and help me with this, and the advicer said that it maybe a android issue regarding the keyboard not showing up, so adviced me to let the battery drain then charge it up and see if that helps the problem, as i can't reset the device it's going to be a long wait untill it runs flat, when i press on the power button to and try and restrat the device all i get is a kind of whistle tone,

regards
edd