I was not told about the limit of my account

On the 8th June '15 I took out a Smartdata 3G mobile router, which is supposed to give me 3G anytime data and 4G nite data for R199.On the 15th June 15 I called Cell C as I could not log onto the internet. I was told that I have reached a R2000.00 limit and my line has been blocked. To my amazement I asked, what limit as I was never informed about any limit when I took out the router. The agent then said the limit is automatically set according to affordability. But my question is should I not have been told about this!! if I was told I would have definitely decreased the limit. He further advised that I still had 2G anytime data to use and nite data I haven't used, but how do I go on using from the limit if I still had more than enough data for me to use...it doesn't make sense! I went to the store and asked Lee Ann how come she never advised me about the limit, she called the call centre about my complaint and they told her the same thing I told her. Lee Ann said to me she didn't know about the limit that's why she never advised me. So my question is, if she, the consultant didn't know her job, who is to be held accountantable for the R2000.00? Why was I not told about it?