Mtn

I took out two new contracts with mtn end of last month, leaving me with four big contracts with mtn. A week later my devices were barred as I supposedly had spent in excess of R2700 on data. I've had contracts with mtn for over a decade and never had this happen. I am aware of how billing is done and avoid costs over and above my contract. After running up and down to the mtn sh, making hour long phone calls to customer care, I had received no help at all.
A week later my bill was over R4000, you explain how that can happen with a barred device which isn't even connected to my laptop.
Then mtn says if you want this sorted out you must wait until the account closes on the 13 th. So according to mtn I owe them money yet they cannot do itemized billing before 13th. So how do you know I owe you the R4000 plus? Sounds like a to get money to me