iPhone 5 on iOS 7 not receiving phone calls

So my friends have been letting me know they can't reach me on my iPhone 5. I'm using Koodo and I've never had this problem before. I tried from my own home phone and it's still not receiving any phone calls, though it seems that I can make phone calls without any problems.

Has anyone else had this problem occur? I really would love to get back to enjoying my phone for it's main purpose.