Harrasing people

I have been getting calls for the last 2 Months going for 3 Months where the are looking for a MARISKA BOTHA and that is not me, for the last week they started WHATSAPP'ing me the first whatsapp send me a warning of being in dept and need to pay before they take legal Actions against me, when I rep**** that its not me the person rep**** by saying they will remove me from the system then after that I got another whatsapp from a different number telling me they are on the point of taking legal action etc, When I called the company the first lady said she will call me back and sort it all out,, still waiting, when I called again the second lady was very rude and started raising her voice at me and the manager did not want to talk to me when I asked. THIS IS GETTING OUT OFF HAND!! I have no idea how they got my contact details BUT, I'M seeing this now as harassment !!!