Having a problem canceling a contract

I have a 24 month contract with Cell C which was due to end the end of April, however due to unforeseen circumstances I decided to cancel my contract with Cell C before time, I called in and enquired what is the procedure and how much should I pay in total cz I wanted to pay up everything, the person that I spoke whom I don't even remember the name gave me the amount and said I will need to pay R298.00 and some cents in total then my contract will be cancelled, she gave me the banking details also, I then made the payment of r300 and sent the invoice through and then did a follow up, they confirmed receipt of my payment and I THOUGHT I was done with them, I called again to confirm whether my contract was then cancelled then I was told no I needed to pay and extra R103.01 they did not tell me why so I said that was fine I asked will that now be my final payment and they said YES after that payment they will cancel my contract. that was end of February, end of March I requested for a paid up letter, for 2 weeks I did not receive a response then on the 15th of April they sent me an e-mail saying my account was not paid up I still owed them R247.77 called in to ask what for