Ipad stuck with icloud backup window - unable to access account

My iPad is stuck with the icloud backup window showing.

Both the Ignore button and the Settings button are ignored (they blink when I touch them, but nothing happens).

I cannot power off. No other icons on the screen respond.

I plugged it in, but that did not change the symptoms.

The wi-fi is working just fine for all my wireless devices.

I have been hitting ignore to the icloud backup notice for some time now since I changed my Apple Password as I have nothing on the iPad that I wish to back up.

Now it is unusable and I need it this afternoon for my facetime with my daughter in Australia.

Help.

Jim