Stop all anonymous telephone calls and ban virtual telephone numbers.

It is a simple matter for telephone service providers to identify both of these types of call and to prevent them from being put through to households; indeed, some companies will do this, at a price; effectively colluding with the "cold callers" to increase telephone service provider profits.
It is difficult to imagine a legal need for anyone to with-hold their telephone number or to pretend that they are calling from somewhere else, both of which actions are a deception.