Incorrect charges due to bundled data - Urgent!!

I have a contract phone with MTN where I have since taken Top-Up contracts in the last 2 renewal dates with the understanding that the applicable fees to the current 2 contracts will be on the fixed-fees that has been around R900.00 to R1 100.00 if badly exceeded without notice.<br> I have thus paid the noted fees as per the contractual agreement with MTN for the last 19 months, and to my surprise around the 11th July 2015 when making a call, I got a message to say my contract number has been suspended and I must contact them urgently.<br> I called their numbers of *** and 083175/6 to no avail, visited their offices on Rivonia Road on the 15th or 16th July 2015 to find-out as to what could be the problem. They could not assist me, and I went to their main offices at 14th Avenue, met Virginia from their Credit Division, and feedback was that bundled charges were due to retrieving either movies or games, and that it has since cost +-R7000. They promised to investigate, and get back to me