I ordered an iPhone5c for 4G usage, however the phone I received displays a 3G on the top left of my screen.
Does 3G on the top left mean I'm using 3G? Does this convert to 4G through proper configuration?
If you see a 3G at the top left it means that you are in an area which does not have 4G support.
When you are in an area with 4G (or, on Verizon, LTE) you will see that in the top-left corner instead.