Re: I'm wondering
@Frank N. Stein,
That wouldn't help. They control the network, so they can make an incoming call look as though it's from any number. If they know, say, the switchboard number for your work (which would be in your contacts list) then it'd show up as the office calling.
Or, as suggested above, if you've got a number for your bank then they can text using that number and have you call the number on the back of your card- normally good security practice- and intercept that call or parts of that call.
Your whitelisting is little protection against this unfortunately.