How do I find the S/N of my phone when I cannot power it on? Further, I do not have the original package. Or... how do I open the back of the iPhone to verify the SIM Card

I bought this iPhone last month and it no longer powers on. (Even tried all those cold startup, etc... without any success.)

I live in Ottawa Canada and it is impossible to bring it to an apple store (Rideau or Bayshore) as they are not allowing clients to make an appointment to return the phone. And trust me, I have been tring to contact apple for these past four days to make an appointment and I keep getting a central phone call service telling what I already know. Not very helpful for sure!

Trying to find valuable help and staff availability to answer your question is like pulling teeth from a live crocodile without being under sedation.

Any way, to find valuable help full guidance from Apple Support or anyone is very frustrating. I should have bought an Android as suggested by my friends.

Any how.... how do I find the S/N of my new piece of crap of an iPhone when I cannot power it on? Further, I do not have the original package. Or... how do I open the back of the iPhone to verify the SIM Card? I'm no technician.