@DavidFo_2105234 Unfortunately, you cannot block such a number. The only thing you can do (and many people do this) is to refuse to answer any calls from an unidentified number. You risk missing calls from doctors, hospitals etc but it is one way of dealing with the problem.
The added problem nowadays is that the scum scammers can often make their call look as if it comes from a genuine number, so you are still not totally protected.
