contract cancellation

Hi. A week back i complained about my contracts not being cancelled. A day later mtn responded saying both my contracts where cancelled as i had suggested. That was not true as only 1 contract had been cancelled and moved to prepaid. However i am still waiting for the other contract to be cancelled and moved to prepaid as well. Mtn being on strike has nothing to do with me as i requested both contracts being cancelled long before they went on strike. I tried the mtn stores as well but nobody can help me. My contracts are over and i would like mtn to alter the billing as the phones are my property and does not belong to mtn any longer. Mtn only has the right to charge me for only the airtime being sent to me which that as well was clearly cancelled. I would like mtn to call me as i have my original documents and will take this further if i am going to be charged for something that is lawfully mine. I was going to take 2 new contracts but not anymore. PLEASE CALL ME