Please Stop Harrassing Me

I've recently been getting emails, SMSs and phone calls (which drop when I pick up) from this company that claims I owe them money with regards to a Vodacom account, whereas I have never in my life used Vodacom and have no idea what they are talking about. I have called them and they acknowledged that it's a *****ulent account but I still receive the emails, SMSs and phone calls. This is borderline harassment.