I live in Canada half the time, so I decided I would suspend my service while I'm up there, and then just switch SIM cards for when I come back. Upon coming across the border, I put my Verizon SIM in thinking it would work perfectly, but it didn't at all. It constantly says 'No Service' and I can't send any messages or make any calls, not even *228 or *611. I've tried restarting my phone, and switching my SIM card back in and out multiple times, but nothing has worked. I have an iPhone 4s. Help!