extention of payment

I took a contract with telkom for two phones. It was on the same day on the 3 of may 2014 n after a few months I realised I was paying more than what we agreed on. I had to pay 449 for each phone but I was paying more. When I checked my statement it stated I was paying an iPhone 5 32 gig instead of a note 3. I contacted them and that was rectified. And I thought it was sorted out and now when I call them for cancellation they telling me I still have further more 5 months to go before they can terminate my contract. And I had called day on day out to see how many months were left for me to cancel my contract. I'm am so unhappy with their service it is too much. Telkom does not respect it's clients