Being Harrassed, Nothing They Can Do

I have been harassed by someone for over a year now who calls me using a private number. The person calls me every day, when I pick up it's just someone breathing. I know, sounds like something from a 90s horror. This has been going on for more than a year and I finally decide to call vodacom for help. The lady tells me I need to go to the police because there's no way for them to see what number it is, and my first reaction is "are you S#!+ me??". At once she started yelling at me accusing me of swearing at her. Had she given me the chance to speak I would have told her I am not ****ed at her I am ****ed at the situation. But no, she literally goes on like a 3 minutes rant about how if I keep talking to her like this she will hang up (at this point she's basically talking to herself because I can't even get a word in). I finally get really irritated and ask her name but she refuses to give it to me claiming it's not important. I'm now at a point where I'm furious so I just hang up on her.

I use the words ****, ****, damn sometimes even f#@k as part of my vocab, and have done that many times on call centres all the time which are in no way directed at the person I'm talking to. Her reaction was extremely insane considering I am literally scared about who the person that keeps calling me is.