Is there a way to block restricted numbers on your cell phone without changing your number?

The phone company can’t help me.

I get these harassing restricted calls at least 3 times a day. I like to have a phone in case I need to use for an emergency and I don’t want to change my number.

I wonder why there isn’t a blocking option on the phone itself? Do phone companies leave this feature off on purpose or do they not have the capabilities to block annoying calls?

Or is it the manufacturer of the cell phone that’s responsible?