This may be a silly question, but. I just received a nice pre-owned Galaxy Tab 7" (Verizon). When I start it, I'm prompted to choose English or Espanol. After selecting language i'm taken to an 'Activate your device' screen. Pressing the 'Activate' button causes the unit to sort of dial out. It always returns 'Activation Unsuccessful, please try again or call customer service'. How do I exit this step to use WiFi only for the time being. I wanted to test it on WiFi before getting the Verizon data plan. Pressing any of the 4 function icons at bottom does nothing... Any suggestions?