No sim card received and the contract is over???

i had taken out a contract with cell c over 2 years ago. i have yet to receive my sim card. eventually i stopped paying it and told them that i wont until they sent my sim card. no sim card but they have listed me with a collection agency despite the fact that i have made the payments afterwards. I cannot get a hold of their legal department. It takes forever. I am extremely disappointed as I have made numerous calls about this sim, they had sent one initially and i spent a whole day trying to activate it only to be told later that sim was supposed to be sc****d. I need someone to call me urgently to sort out these payments i have made as i want nothing more to do with cell c in future and i would also like to know how they plan to resolve me not getting my free minutes at all when i had wanted to use this for business but was forced to use my own airtime