Mtn *****ing once again

Once again they deduct the wrong amount of money! They have been doing this for 3 months! I have a modem with them for R239 And a sim only for under R100 How can they deduct over R500 eac month? And they set it in store that my bill can't go over when data runs out.

This is tough times and I can't afford to pay extra for nothing. This is totally unacceptable. That theft. Nothing other than theft!