OVERCHARGED - NO REASONABLE EXPLANATION

I was overcharged on my monthly subscription fee. I called to ask why, and I spoke to one of the consultants, Nontobeko, who explained that it was because I was "roaming on the MTN network" and this incurs additional charges which are out of bundle. I explained that I was not informed of this, and had I known, I would have taken precaution. Obviously. I was told that I would be receiving 30GB of data per month for the months of September, October and November. I am meant to pay R499p/m. The September bill was R1700.

Still no response to me from the email sent to **********