unwanted telemarketer - how do I get them to stop????

Today a person from (423) 341-2697 called and asked for my husband who was not at home. When I asked for his name he mumbled it. I then asked for his company which he refused to tell me.  He kept repeating that he wanted to talk to John. I told them that I would not allow him to speak to my husband. At that point he said, "F*** you" to me.
I hung up.
He actually called me again about 20 minutes later. I did not answer this time.
I DO NOT WANT TO GET ANOTHER TELEPHONE CALL FROM THIS NUMBER OR PERSON!

They won't stop calling.  But, a call blocker might be of some help.  Also don't pick up on numbers you do not recognize, or where there are caller IDs that seem odd.  Or where there is no caller ID.  There’s  no way to stop the calls from being initiated. Calls originate in India and Pakistan and they spoof local numbers.