wrongfully blacklisted

My account was paid up after my last order in April 2015. I decided not continue with selling anymore after I paid up on Monday 18 January 2016 they phoned to let me know I was placed on ITC for owing them R4286. Just last week I paid R100 because I was told current invoice showed R100 I had no idea why or what was going on,since my account was paid up. And I stopped selling since I had problems with customers not paying. If they checked my credit record they would have seen im clean and a good payer because of them that my payment was never credited into my account my name is now on ITC for something I did not do as they are saying I did not pay. I want my name removed from ITC before the end of this week. And thanks to this site I found out in not the only one wrongfully accused of such madness.