Threatened with being listed with ITC just because I demanded my deposit refund back

Since I have challenged the company to refund my deposit, I have been threatened with the following message.

R2,970.97 STILL OWED TO THE LANDLORD BY YOURSELF, please advise when this will be paid, failing which we will list the amount owed on your ITC record.

I need your intervention in this because this is really out of control, innocent citizen are being ****** out of their last hard earned penny by companies that think they can do as they like.Threateaned