Slow service & Horrible experience with Cell C.

I requested to upgrade my contract in the month of October 2015 after I was informed by the provider that I am due for one and there has not been any feedback on the matter.Then I called through to follow up,then I was told that there were out of stock,which then I decided that I no longer want the upgrade and it must be cancelled,that was after 3 weeks of waiting for the upgrade to be done.I was then told by the agent that a case will be logged and I will be called with the next 48 working hours,however that did not happen,then I called again this month,as I received an sms that my contract is ending next month in January.I decided that I was to cancel the contract seeing that I am not a happy customer,then I called in to cancel,was advised that I needed to cancel the upgrade first,which I did and never got feedback,the agent logged another case for the upgrade to be cancelled & the same turnaround time was given.I then decided to call again yesterday & I was transfered numerous times until I spoke to an agent who goes by Samu,who did not know her story and she also wanted to transfer me to again,I refused and asked to speak to her manager and she ended the call in my ear. HELP.