Enter into a contract online but not cancel one???

On 11/12/2015 I upgraded my contract telephonically and was told that RAM couriers would deliver the new phone to Herm**** by 15/12. Stayed home all day but tracking number showed phone sent to Worcester. At 16h30 that day I phoned Vodacom but no-one was able to find out what was going on. I was then told that the phone would be delivered on 17/12 but that RAM would phone me to advise approx. time of delivery. By 09h30 on 17/12 I had heard nothing so I phoned Vodacom again only to be told delivery would be done on 18/12 but no approx. time of delivery could be given. I told Vodacom to cancel the upgrade deal in it's entirety but was told I could not do this. I wrote an e-mail to Vodacom on 17/12 setting out my frustrations and requested cancellation. No response received. I then went onto the Vodacom site and chatted to Ashlee the consultant who promised me that I had been treated badly and she would escalate this complaint to priority status. That was the last I heard from Vodacom until I received an invoice indicating that my bank account will, be billed on 31 January 2016. I spent an hour on the phone - at no stage did a consultant take my details and offer to sort it out.