I am never getting a cellphone contract with Cell

I am so irritated by Cell C. I took a cellphone contract with them in April 2013. Last year I decided I was no longer interested in having a cellphone contract, I walked into a Cell C in Sandton City and told them I was no longer interested in my contract and that I wanted to settle my phone. They gave me the settlement value and the account number to use when i am doing the bank transfer. they also advised that i should call 140 to check if the funds have been received. I did the transfer and called in cell c the folowing day and they had received the funds. After then I never got any debit order until recently Cell C started debiting my account in april. i called in to find out why as I thought maybe they have made a mistake and I was told I never cancelled my contract? How so? I realy hate this as I have to keep on reversing the debit orders and this in the long run will have a negative impact on my bank account. Please help me noone in Cell c is able to assist me, when i call in now the consultants pretend as if they cant hear me. i am so so irritated.