Why didn't they set it up there for you?
Sent from my HTC6525LVW using Tapatalk
How many Sims did they try in the store? If it's not a SIM go back and get that phone replaced pronto!
Sent from my HTC6525LVW using Tapatalk
The Verizon M8 comes preinstalled with a SIM card. There's no need to insert one. Did the store take out the one that was already in there? I activated my phone from home on the Verizon website and had no problem. Have you tried to activate it online?
Take it back and get a new one. I wouldn't feel comfortable with that device even if it starts working. It was working at the store and stopped? No thanks, give me another one.