Returns not cleared

I app**** to be an avon rep and was allocated Shonisani to manage me. From the beginning She has been advising me to place orders for my whole credit and whatever I couldn't sell I could return to her and she will send them back and I could pay the difference of items sold, I have been doing that for a couple of months. I'm now receiving messages saying i havent paid last return and that i owe R1800 but I returned and paid the difference. I forwarded the messages i received from Avon saying i'm owing , she kept on saying she will sort it out 2 months ago. Now I received a message saying if I don't pay I will be taken credit bereu. Then I contacted her Manager Lizel last week but she was off no help. I spoke to Shonisani again she said she had explained to Lizel the matter but still no change . I have my receipts to proof i paid.