Incorrect billing & poor response

I have not been an active Multichoice customer during 2015. I had a credit balance when suspending my account in December 2014. I recently had a debit order go off on my account (the first one for 2015). I reported the problem on 2 September 2015 but have had no response from Sheilla Khumalo. I additionally sent through the supporting documents as requested. 1) What has happened to my credit balance? 2) Where is my refund on the recent incorrect billing? 3) Why should a mistake by Mutlichoice become my problem? 4) Why has this happened? Please sort this out. Thanks.