I keep getting prank calls from 3 cell phones and they call at all hours of the night and day. Plz help anyone i would be very thankful to you. Thank you for taking the time to read my question. I keep getting prank calls from 3 cell phones and they call at all hours of the night and day. Is there a system that can block them without them knowing that they are blocked? I've heard of companies that will let the caller know that they are on a blocked list from this phone. Plz help anyone i would be very thankful to you. Thank you for taking the time to read my question.