Charged for Cancelled service

I have an Cell C account for many years now. I cancelled the Get more service in September of 2016 only to find out that Im still being charged for it when I got my statement on the 11th November 2017. I have contacted Cell C twice now and this issue is still not resolved. I have even been asked why I pay more than the amount I am supposed to, and was told that it is my fault that I am paying for this service as im paying more than I should. Surely I cannot be charged for a service that I cancelled over an year ago..... I have tried to contact the call centre again today ********** 7 at 08:30am, but lost all confidence that the matter will be resolved whilst speaking to the consultant... Can someone that knows what they are talking about please call me..... I have also logged a issue online with reference number 171 ********** 83. They have claimed to have contacted me, but I dont have record of that...