Cannot Cancel my Contract!!!

I phoned Cell C direct to upgrade my current two cellphone lines with them. The same day I got some terrible news which forced me to cancel/reverse my upgrades. Seeing it was after 17:00 pm I contacted them the following morning. They said they cannot cancel/reverse it and that they will have to send a request for it to be cancelled. They referred me to several different departments and nobody can help me. They said I must phone back after 72 hours. The same day RAM Couriers arrived at my house to deliver the one phone and I sent it back after Cell C instructed me that should they come I must simply return the package. After 72 hours I phoned again in which I was informed that there was no capturing done to cancel / reverse my upgrades and that she will quickly send the request through. I informed her that it is very unprofessional service in which she said I must phone back in 72 hours. All I want is for my two upgrades to be reversed and my current contracts that expires December 2015 and January 2016 to be cancelled so that I can go over to prepaid. This is not the service I expect from Cell C. PLEASE CELL C, HELP ME!! Your urgent assistance in this matter is awaited.