Cancellation of contract Cell C

It took me 7 calls and 3 months to try to cancel my contract from CELL C ,talked to Cleopatra,Nombuso twice even the supervisor Vusi , unfotunately i didnt wright down all the names,everyone promised they would call back which never happen. My contract is still not cancelled.I did all in the right time schedule by phoning more than 1 month for the cancellation to be done. Please help me cancelling this contract as there only intensions are in taking our money.Is there another way i can go than this higly frustrating and time consuming way as your call everytime will take up more than 30 minutes in waiting and transferring from 1 operater to another.