FNB Legal team

FNB handed me over to Barett & Associates regarding my Credit Card payment. I have made an arrangement with Barett and Associated that a amount of R400 will be paid to them every month before the 30th of each month. I make the payment every month as per arrangement but Barett and Associates phones me everyday, harassing me and telling me I will be red flagged for legal action they do not receive payments but on my FNB Credit Card Statement the payment shows each month?? How can FNB hand me over to a company so clueless?? I contacted Barett and associates demanded to speak to a manager but they tell me the manager can only be contacted via email how do I sort this out??