Overcharged for data - no resolution

On the September and October Invoices my data did not cut out when reached it's limit (I have a R50 cut off) resulting in a hefty bill. I was made to believe that this was being corrected. I have tried to call the call centre. Spent close to 30 minutes on the line being transfered from person to person and not receiving resolution, or getting the line disconnected. Kindly credit my account for the over charge over the two months. Should this not be corrected to my satisfaction I will be canceling all my business lines with vodacom.<br> <br> My lines have been suspended and I do not take to vodacom holding my business hostage over their own errors likely.