It's in something called "Network Settings" last time I check in the samsungs

Depending on the brand of phone, in the phone's call settings, there is a menu option, where you can restrict incoming/outgoing calls, which people use when they want ALL incoming calls to go to voice mail. All this feature does, is shunt all calls (not just certain calls), to voice mail. So while you are sleeping or in a meeting.

It can also can be used as a security feature, so that if your phone is lost or stolen, it can't be used to take or make call even when changing SIM cards, since it's a phone feature vs a SIM feature, but of course if the person that steals or finds the phone has any brains, they can turn these features off (unless their lockable with a pass code).

Not sure if your phone has that setting built in or not (you can use the call forward feature to do the same thing).

No carrier that I know of, can restrict incoming calls, unless it's required by a court order.
The way I get around it, is by making a blank (no sound) ringtone, and assigning it to any incoming calls I don't want in my contacts list. I never even hear the phone ring.
This doesn't stop the caller from leaving voicemail or a text message, but most carriers can block text from specific numbers.

Is there a way to restrict INCOMING calls? I can only restrict outgoing calls, but why would I want to do that with outgoing calls? Grrr. So is there a way to restrict incoming calls on a Samsung A470?