I've recently been using an iPhone 5 with verizon, it works fine, but is a bit slow and I decided to upgrade to an iPhone 7. I bought it from eBay from smarter-phones, it's fully unlocked. When I transfer my SIM card from my iPhone 5 into my iPhone 7, it says verizon in the top left corner, not No Service, sometimes it has 0 bars and sometimes it has 1 bar, but I can't make any phone calls, they all say call failed. I've tried resetting my phone, re-inserting SIM card, manually selecting carrier in settings, etc. I'd assume it doesn't work if it said No Service with 0 bars all of the time, but it says my service provider (verizon) and sometimes has 1 bar, so I'm not sure what the issue is and why it isn't working.