Pathetic Vodacom Call Centre assistance

I have been trying for more than ten days now to cancel a future order, which requested my phone to be changed from a contract phone to a pay-as-you-go phone. I want to cancel the order since I have decided to rather upgrade my cell phone with a new contract. Four phone calls later to Vodacom's Call Centre and the future order has still not been cancelled. Every time I am promised that the order will be cancelled within 24 hours, and nothing has been done yet. The online consultants also refuses to give me a reference number. I need to upgrade my phone before I go on an overseas trip early next week and no one seems to be able to help me. Pathetic services, I don't know what to do and the Vodacom shops can also not assist me.