OVERCHARGE

I recently upgraded to a "Made for Home 400Gb" at a special rate of R499 per month. I have sent through 3 requests as to the reason why I am now charged R 607 per month. Not one of my requests has been answered or acknowledged. I went to look for the web pages on which the specials were advertised but they have since been removed. This is really bad for a company such as MTN. I have finally resorted to this platform to get some answers.