Cell C not cancelling my contract

My contracts with Cell C ended end of September. For the last 3 months I have been trying to cancel my contracts as I am unemployed and can no longer afford to pay, but every time I attempt to cancel there is a different story. I phoned them on Monday explaining my situation and all they said was they're sending an email to a different department on my behalf and they will call me back within 48 hours to cancel my contracts, but I'm still waiting. This is causing me extreme emotional stress at this stage as I tried to finalise everything when I still had the money to do so, but now I have to take food from my children's mouths to pay my cell phone bill every month(which is now also mysteriously higher than what I signed up for), because it is impossible to get a contract cancelled with Cell C.