Because of Cellc's inefficiency im now on "ITC"

My contract was paid up to date, but because Cell c did not allocate the money correctly and without any notification to me I was handed over and put on "ITC" as a bad payer. I feel this is unacceptable because this is not my fault at all and now I am on some list even though I was on track with my payment. I need them to clear my "ITC" and my track record.