City Property blacklist their tenants ********ly

I have been renting with City Property for almost three years and everything was good. It has recently come to my attention after my lease was terminated, when I wanted to apply for a rental with another agency, that City Property had been listing me on the credit bureau as a late payer and it shows on my credit profile that I have a debt with them. I tried calling and I also sent an email, however, nothing is happening. It puzzles me how they listed my name with the credit bureau as a bad payer when I pay my rent religiously 5 days before due date every months. They are doing this intentionally so that I cannot qualify for a bond not with another rental agency so that I can always resort to them for rental. Disgusting!!! I will be referring them to the Credit Ombuds.