Doesn't the discover use a regular sized SIM card and the Moto E uses a micro SIM? It wouldn't even fit to begin with. You need to get a micro SIM from a Koodo store or retailer for $10 + tax, activate it online through Self Serve, and then pop it in your Moto E.
Ah okay. Yeah if regular sized SIMs aren't cut exactly the same way that a micro is shaped then they won't be recognized by the phone. I had that happen with one of my customers when I was at Mobile Shop last year.