Usless and pathetic

This irritating and useless companies agents keep Calling, Either they would be looking for a Lushar or so, and the more I tell these brainless idiots they should check the number the more they harass me. Or they would call for 5 seconds and hang up. or the operator would phone and act like a stalker and all you hear is breathing, after all is said and done they would send a sms stating that "our useless and pathetic agents cant get hold off you" what can I do to report these useless and brainless idiots because I'm getting fed-up with their harassment