In Arrears over R36 - Ridiculous and not even my fault

I haven't bought anything for the last 4 months if not more. (Except for last week) I received a message, my account is in arrears for R36. I went into Foschini's and asked them for what is was, they told me it was for the notification or something, i don't know. I told the lady to take it off, because I'm not going to pay the R36 or you can close my account. She phoned in and took it off, but the problem is not over yet. Now Foschini's is still phoning me, 10 times a day, 7 o'clock in the night to tell me my account is in arrears for R36. The lady who phoned me, doesnt even know for what the R36 is, they just want the money. I dont have a problem to pay something if I had bought something on my account, but my account was clean for the last 4months or more. The service is ridiculous. There are thousand other people who's account is in arrears for thousands of rand and Foschini keeps phoning me and asking me why I don't want to pay the R36. REALLY???? I will take back the dress I bought last week and then I will close my account if this is not sorted out. I want my named clean.