Terrible service from Vodacom

Worst service from Vodacom. I app**** for a double deal contract and received the bother devices. Upon receiving it I found that I did not get the voucher that was promised and the devices were not dual SIM phones. I therefore requested for cancellation fee for the contract and collection of the devices. On the 15 July I received a response advising that they need my ID number and collection address to which I provided immediately. On the 17 July they confirmed that collection has been arranged and that the ticket for cancellation has been closed. On the 22 July RAM couriers collected both the packages including the SIM cards(***) Between the time of my initial cancellation email to date, I have sent numerous emails to confirm that I will not be debited and that cancellation is finalized however Vodacom did not respond to any of my emails. I was then debited at the end of July which should not have happened and today I receive a invoice from Vodacom for August meaning they will debit me again. I then called Vodacom and was advised by the agent that the contract is not cancelled on the system. So now I am paying for something I do not have and did not use. I should not have to waste my time and money chasing up on a cancellation that I was told was done nor should I be trying to get a refund for a debit that should not have went through. So if the cancellation is not complete as I was advised, that means I will be having to try and get another debit refunded come this month end. What exactly am I paying for...does Vodacom just take money from people and rob them blind.