Data valildation report not sent after requesting it 7 times in the past 17 days for being overcharged

I requested a data validation report from MTN with regards to my data contract and wifi modem with them. I have logged 7 calls via 808, but they are proving to be of no assistance and I not received the report yet. Every time I call, they say that the report will be sent to me within a maximum of 2 days. One when I called they said it's under investigation and they cant send the report, but i insisted on it because nothing should change on that report given that is my URL report and they agreed, but still nothing. Today when i called, they said perhaps there is a backlog. Looks that's there's a backlog because MTN is over charging numerous customers!!! I had set a zero limit in April 2016 on this contract, and I did not use the wifi modem for the entire month, except for about 1 hour on 15th April 2015. It was impossible for me to use the 2gb that comes with my contract monthly in that time on that 1 day only, but my bill amount to R 1055.65 on my statement for the 10th April 2016. I have been requesting a data validation report since the 13th April 2016. It's unacceptable that when they clearly overcharge you they don't assist you or even attempt to correct their action. I definitely wont be renewing any of my contracts with them!