Can't upgrade contract... Can't cancel contract... Now what!?!?

I'm once again highly frustrated with your service... I ordered an upgrade on the 16th of April and due to the fact that the department sending out parcels did not put addresses on the parcels I had waited two weeks for my order when I just decided I'd had enough and sent through a cancellation form to rather cancel the contract due to really poor service. As I could not even get my letter of cancellation through to any of the departments I decided last minute that I'd give the upgrade one more try. I ordered an upgrade last week Friday and have since been told that I cannot upgrade until the previous order has been cancelled... It's once again been two weeks since I requested them to cancel the previous upgrade and I'm still waiting. My contract end date is on Sunday. What do I do now? I have really just had pathetic service from Telkom with this upgrade story. I have decided to go to MTN in the meantime to see which devices I qualify for. If I do not get feedback from Telkom by tomorrow I'll be going with whatever device MTN gives me.