Insane Airtime and DATA billing (Very Angry)

I've purchased 2GB data budles on the 25th/03/2015 which the data didn't last me at least two weeks, which it frustrated me the most, I contacted 173 several times which one of the consultant gave me **** telling me that my applications are running that might course the DATA to get finished which I advised the agent the past mpnths I have been using 1GB of DATA with the same settings however the DATA last me for more than a month, the after bought 500MB which also didn't last two weeks then bought R30 airtime which i didn't make calls that can even cost R2 but the airtime is nowhere to be found which they busy sending their FREE PROMOs airtime and data daily then next day you find that my balances keeps decreasing I almost spend R 500.00 in less than a month that MTN charged me which they need to explain how is this month is different from other months which i don't do things different from the other months, I WILL NEVER SPEND R500 in one month to access communication with MTN this is the first time this is happening I'm VERY ANGRY if they are not willing to come back to me urgently I will gladly report the matter to ICASA and the Ombudsman for further assistance