credit not being returned

I went under debt review in 2014. I enquired about a settlement amount end of July'15 beginning Aug'15. I got my statement from my debt counsellor with the outstanding amount. My last payment made by debt counsellor wasn't reflecting with Foschini yet. According to consumer friend the last payment they received for Foschini was on the 9/7/15 so the payment made on 3/8/15 wasn't reflecting as yet. I subtracted this installment from total outstanding and paid the difference. I called consumer friend to get paid up letter on 3 occasion. Finally on the 24/8/15 I got my paid up letter. My debt counsellor made a mistake and paid another instalment end of Aug beginning Sept of R156.47. So there is a credit on my account. Since then I have been struggling to get this money refunded. They keep telling me there is no credit. How can that be if payment was made after paid up letter issued and account closed. I have various emails and recorded calls about this. Kenneth called 3/3/16 and said he is investigating and will come back to me. No further feedback. Just convenient to say there is nothing further they can do! Just take other peoples money!!!!