UNKNOWN/BLOCKED NUMBERS According to the Komando website, that old landline trick still comes ... Once you have that number, you can block it on your phone so the person can’t call you anymore.

Your Samsung Galaxy makes it easy to block phone numbers from telemarketers or other undesirable callers. You can block all calls from private numbers and block specific numbers as well.

Try this on your landline. Make sure your caller ID ... then tap the circular information icon on the right side of the number you want to block. On the next page, tap "Block this Caller" to ...