UNIFI false loan claim

I have for a very long time been receiving SMSes from UNIFI for payment of a R14000 loan. I have never received money from UNIFI and have never app**** to them for a loan. It has been nearly 10 years. For 8 of those 10 years I've had a Debt Review Flag on my profile which I am currently dealing with. Both Experian and Transunion do not reflect these on my credit report. I called them to enquire as to what was going on. They clearly think I owe them money and have made a serious effort to appear on my credit report. I really need the harassment to stop. I sent them two emails requesting them to rectify the error on their part as I will not pay for monies I did not request of receive from UNIFI.