TERRIBLE SERVICE & DATA USAGE

At the beginning of March 2015 I upgraded my phone at a Bloemfontein branch and got a new Samsung S5. They activated the phone and set it up for me. My billing account runs from 11th to 11th, therefore my new month only started on the 11th. Yesterday I got a shock telling me that I have reached my limit of R2608 - what the hell???? I immediately called your call centre - hang on for 35 minutes and eventually had to be put through to another (accounts department) where the music is so hard you had to take the phone from your ear. After another 25 minutes I gave up and dropped the phone. Now let me make it clear - you can check my records over years with you - my account is never more than a R1 000 - I will take this to the highest authority - I will not pay for someone else's mistakes - I only use data for what's up and Facebook and have never used more than my 500mg which I get free. I need this sorted out as soon as possible - according to your call centre this data was used in setting up the phone. I specifically asked them to set up the phone as I am clueless. I want this matter to be resolved TODAY. I also have an issue with a setting - again 20 min and all I got was an