borderline harassment

A few weeks ago I received a call from someone trying to sell me some plan that has to do with car protection anyway I understood the guy was doing his job so I very nicely told him that I am not interested a few days later someone else called for the exact same thing I told the lady I received a call already and I'm not interested but these people continue to call me I don't know what their problem is are they just *********** or just want to harass people who have no need for their products but it's really frustrating please I need u guys to put me on your do not call list I know about this company and have no interest in doing business with u.