pathetic Customer service

I had a 24 month contract with Cell c than in December I called in requesting for a settlement amount and I advised the consultant that I will the account offwhich I did same day and I requested that once the pmt reflects they have to send my paid up letter and cancel the contract and shift me to prepaid offwhich they agreed to do well they send me a msg that my contract had been cancelled and thereafter I was on prepaid January I'm receiving a statement that I need to pay I have sent the emails to Customer care asking how is it possible to cancel the contract while I'm still owing n put me on prepaid? Secondly no one told me about cancellation fee if you settle the account before time even on the copy of my contract it's not there so the service is pathetic and I'm still going to take it further I won't pay that cancellation fee and the worst part is Anthony the consultant tells me that on the settlement amount they didn't include my Dec usage off which I'm not going to pay again bcs according to my knowledge if I requested a settlement amount n a paid up letter it must clear that I don't want that account anymore.