Cell C removed my data limit without any notice

About a year ago, i phoned the Cell C contact center to set up a data limit on my contract. This was confirmed and my data limit was set to not go over my monthly data bundle amount which was included in my contract. Earlier this month I got received my monthly bill only to see that I had been charged an extra R155 for data. When I called into query this extra charge, the consultant who helped me said that there was never a data limit set on my contract. I said that i definitely set one and remember calling in early last year, but she reiterated that it had never been set. So due to Cell C's negligence, I now have to pay on extra amount for data. I feel that Cell C should reverse this due to this mistake being made from their side. My reference number for the call earlier this month is: ********** ********** 70