Not pleasant experience from rental agency

I am not one to give bad reviews but I am really disappointed and annoyed by the service I am in receiving from this agency,I joined in December and made every payment upfront and when my rent was due I paid in advance as per agreement,I received my statement showing that I am owing R2400 ,i attempted calling the account keeper Moses ,I tried contacting all details on the statement,eventually I contacted the rental agent who I explained that I paid as per the amounts given by her,we agreed that there should be a mistake on the statement and I am not owing anything,I then got notified still that I am owing and was advised only Moses can clear the situation after many attempts off contacting and WhatsApping I could only get through via a WhatsApp call,with an arrogant tone he stated that he is a busy person making my enquiry feel less important,when I expressed my situation he had a no care attitude not responsive to myside,eventually he agreed to have a look and get back to me.I then got a letter under my door stating that I am to pay or else legal action is to be taken against me,days later the care taker send me a WhatsApp stating that “at the office they want to know when you going to pay”.Today I received a Letter of demand via sms for an amount that I do not owe.Till today I have not heard from Moses after trying to contact him numerous times I even WhatsApped him and he bluntly ignores me.This is only the start of a new relationship with rental agency and if it is like this I am scared.The only pleasure I get is from dealing with the rental agent Kenelo who is always kind and responsive with great service who also attempted to resolve issue with Moses but has limited control