RIDICULOUSLY HIGH DATA BILL

My bill has increased from Jun 2015 from around R1000 (which even then was ridiculous! I have WIFI and barely make calls / use sms's), slowly creeping up and up, (even though I have restricted my settings, deactivated mobile data to the point that I might as well own a brick and not a cell phone) yet I am still being billed ridiculous amounts. I waited for my ugrade in April to increase my package to counteract these ridiculous bills, I asked my husband what type of contract he is on with Vodacom as he never pays such excessive bills and he uses his phone far more than I do for business (downloads galore, phone calls in way excess of mine). I have taken as much data and call time as my husband with my new contract - 24 MTH My MTNChoice 200mins which includes R509 CHG+(S200+D300). I asked MTN if this will assist with lowering my bill, and was assisted with this package. I AM NOW PAYING IN EXCESS OF R2000 A MONTH! I WANT ANSWERS AND CREDITS! I accepted to pay R795 a month - NOTHING MORE! I know this is a MTN issue as I have friends and family also complaining about MTN and their DATA **** costs! I want this resolved! I want out of this contract! I am bitterly dissappointed with MTN!!