Hello. I posted a couple weeks ago about my phone time traveling and thus causing a multitude of other issues. Verizon gave me a new phone but I still had the same issues - which made me conclude that it was my SIM card since I used the same SIM card in my "new" phone. I do have another Verizon SIM card - brand new, never used still snapped in it's little card thing. Can I just switch out the faulty SIM card for the unused new one? Will I lose stuff? What exactly does the SIM card do? Should I go into Verizon for this? Or can I just do this now?