No response even though account paid

My account was handed over to the legal department without my knowledge of that, I only discovered this when I went to check my credit on the credit bureau. No statement has been sent to me in the past year and no communication was sent to me with this regard. But anyway I took it upon myself to settlement my account, I sent numerous emails requesting anyone to get back to me which they never did. They only came back to me when I sent threatening emails. I made a arrangement to settle the account and paid half the amount the next day I was called back to say the amount has been received, 2 days later I paid the balance and they promised me that it would reflect after 2 days after numerous phone calls and emails that balance has still not been allocated. Can you people please sort this out you are messing with my lively hood