Forced to pay for a lie

MTN phoned me regarding an upgrade on 1 of my contracts. The lady on the phone said for only R119 a month we would get 70Mins and 12GB of data. This was not the case, the contract that i ended up receiving cost more and im getting alot less. Ive phoned them and reported i even have a case number. ive been to local shops and they said there is nothing they can do. I ended up taking out another contract to get my wife sorted. Nobody has phoned me back regarding this either. This is not the service im use to from MTN CASE NUMBER: RCO294414