Settled account/yet told that I owe

I am so angry. I have been getting calls from ***, and I have been patient. I don't understand why I need to repeat myself. I'm hoping that these people have a system that they should be recording for every single call they make. I cannot keep on repeating myself. What's even worse is that I am being called and pestered over an account that I don't even owe. I have settled this whole account and now Im told that Im owing R152.