Complaint to Afhco property management

I had a joint contract with above company in 2019 ,when my contract ended I moved out ,my deposit was paid after 2 months of moving out after a long struggle with them,last month I made an application to their other unit to my suprise their consultant Ruth advised my application was declined as I owed Afhco R75000 ,I immediately called their office which confirmed my record with them is clear I dont owe them anything ,as per Ruth advise i emailed Jessica whom she advised was the person who declined my application due to the amount i owe their company,to date she has not responded to any of my emails, I also requested assistance on their WhatsApp service that they send me a written confirmation that I dont owe them ,till to date I have not received anything and now they are avoiding me.i just need them to confirm in writing that I dont owe them and also explain why was my application declined based on that.