Matter escalated - one week later still no feedbac

For two and a half years, up to November 2015, I had always paid inbundle rates only (R154 and now R159). However, at the end of November MTN slapped me with a heart stopping bill of R6140 for data usage on the contract. In the interim I have asked my bank to reverse the amount. I was under the impression that the data package was capped <br> <br> I had lent my ****le to a friend's son to provide him with access to the Internet while he prepared for his school exam as I was under the impression that the account was capped at 2gb. The child does not reside with me and I was therefore not aware of how much data he was using, but no sane person would have agreed to usage of R6000 on a contract that had up to November only incurred charges of R160 for the previous two and a half years. <br> <br> I have taken up this matter with MTN on several occasions with no resolution so far.<br> My reference number with MTN is ***4 and the matter has been escalated. I have however heard nothing except that interest is being added. Please help.