Cell phone provider call logs

So I had someone call me with their number and their name showing up. When I look at my monthly bill with verizon, that number does not come up at all.

I can literally go through my phone history on my phone and find the exact time, date, number and name and screen shot it.

Why would it not be showing on my phone bill call history?

I was thinking they used a app like whatsapp or google voice but are their any apples phone apps? I know with whatsapp and google voice your name may or may not pop but your actual telephone number definitely will not show.

Anybody able to help?