Constant Harassment - Possible ****mers

I keep getting harassed from this company saying I am owing Tracker and I must pay them, I have never had agreement with tracker, only through my previous insurance and even they did confirm that I do not owe Tracker and that I certainly do not owe the previous Insurance company either.

I do not know where they get my details from but this seems like it will be a case for the Obudsman as they have some intrusive information such as the last digits of my banking details which I wouldn’t have volunteered to any Insurance company or any account I have taken, this sounds like it is a **** and I’m definitely being harassed for something I have no knowledge about and would like to see the end of it as even when I mention to them I’ve sorted this out with the Insurance they insist I need to pay them.