Listed on Credit Bureau for account that's been paid

I took a watch with Teljoy via Discovery Vitality, I then changed my Vitality from Active to Full Vitality and I was still deducted the premium even when i have reached my goals. I reversed the money deducted for Aug then consulted Discovery which advised that the issue is with Teljoy. I then took it up with Teljoy who found out that the Full Vitality was not giving discounts for the watch. I then paid back the money in full. When i check my credit score, Teljoy has listed me that my account is in arrears. I have paid the account after the issue was resolved, why am i being listed? I sent an email to their custormer service department, to date, I have been ignored.This company is a nightmare. I just wanna settle my account and never make business with them.