I am a landlord that uses their service to perform...

I am a landlord that uses their service to perform credit checks. When prospective tenants apply online, we are due part of the application fee. They consistently hold our portion for 45-60 days. I have tried to talk to the person in their billing department and she almost never calls me back. I have tried to talk to management and supervisors about this procedure. I am still owed money from August 31, 2019 and it is now October 22, 2019. I am now looking for a new company to conduct our credit checks. I am highly dissatisfied with this company and dissuade any landlord from using them.