Threats and harassments from service provider

I am a very loyal and committed client of Mix telematics tracker company. In Dec 2022, I requested road assistance from them. Later in the month, they sent me a statement saying I am owing them R1049. I called them requesting explanation of the amount I am owing. I spoke to an agent and tried to do the breakdown of the R1049 which I could comprehend. They asked if I could phone the towing company (My Way) to get clarity. I made it clear to them that I won’t settle the account until I get all the clarity that I need. Later in March 2023, I was called by their lawyers offering me 50% discount which I paid. An agent from Matrix called me the same month saying my account is up to date that going forward they will only be debiting my monthly premium. I kept on receiving threatening and harassing messages that I have an outstanding of R549. I called them again and the first agent said that I had paid the discount after the agreed date, hence still having the balance. I was transferred to accounts department and was advised that my account is up to date, not owing anything. I received the same harassment SMS, called them again spoke to Palesa the supervisor and gave a different story, saying they are owing me that amount of R545. My main concern, frustrating issue, is them registering my name with all credit bureaus. I am taking further steps against them for tarnishing my name, threats, and harassment they made. Should I not get credit due the blacklisting, Matrix will be held liable and provide for more financially.