touchscreen unresponsive to double-tap; unexpected actions

I have a brand-new ZTE Legacy. When I called QLink for help, they referred to the manual, like I had not thought of that..... When I said I could not find my answer, I got "Your phone service will end in 30 days if you do not use it." I received no other help.

At Home screen, it commands me, "Double-tap to unlock." Double-tapping does nothing, from a quick tap-tap to tap....tap, of differing lengths. The screen at the bottom said, "Long press screen to unlock."

It seems to reset quickly, maybe 15 seconds, bringing me "Home" when I hit the button on the side to power up the screen again.

Three fingers on Home screen for like two second brought me to a screen saying, "No recent apps." Another three fingers on the phone for another two seconds brings me to Home Screen 2. Another three fingers for 2 sec bring to an unnamed screen but says, "Button 24, unlabeled, " containing a mini-image of Home Screen 2.

Phone screen powered off again while writing this, bringing back Home. When I hit phone icon, it states, "Phone. Double-tap to open," which opens nothing, does nothing.

I have also remove and reinserted the battery a couple of times and this did not help either. The buttons on black exterior at the bottom also do nothing but represent, "Back," "Home" and "Menu."

This is just an endless loop of useless functions. Any suggestions of getting the this phone to respond would be appreciated. Thank you.