Cancellation information not as per the way contract was sold to me

Beginning of September I was dealing with Zenande a sales consultant who told me about a special that was running at the time where I will not pay for September and will pay R400 per month for the rest of the year and only in Jan I will be paying R800 which was a discounted price due my medical aid. In November I requested a cancelation as I have changed jobs and I was told I will need to pay R3100 cancellation fee within 24 hours which he never mentioned to me when I asked him how cancellation worked. I was told that I will only pay for the next 3 month`s fee cover should I cancel which in my mind was the R400 for the two months and one additional month of Jan which will be R800. When I called the call centre I was told cancellation only works on full amounts which I was not told. On top of that, I was being debited R540 which was not the R400 special I have been told about. I tried getting hold of the sales consultant who has ignored all the questions I have had for him for all the discrepancies. The energy the sales consultant had when he was selling me the contract has now disappeared since I have been wanting to cancel. I am now getting calls from a debt collector that I am owing but no one is prepared to provide me with answers for the information which was omitted to mislead me and ********* conduct of consealing information regarding cancellation.