Impossible to cancel Contract

I have been trying to reach the Cell C cancellations department, to cancel two contracts, since last week. Each time I’ve called the cancellations department, I’ve had to hold for on average 10 minutes with no assistance. I then decided to choose a different option, viz, ‘upgrade my contact’ and my call was answered immediately. Thereafter I requested to be transferred to retentions, only to get the response ‘the number you have dialed does not exist’. I just want to cancel my contacts, but it seems like it is purposefully near impossible to do, not to mention the amount of airtime I have wasted.