Customers Service - no response

I phoned customer service on 17 November to query an amount of R842 I was charged for internet data for BBM usage. I send 1 -3 BBM's per day. Looking at my history the average use is about 10MB per month. How can it be possible to use that amount of data for BBM. I was told that I will receive a call within 2 days. Nothing! I phoned again on the 20th November and was told the same - still no call! Ref. no. given ***.