Vodacom - Non-existent customer care.

Vodacom refuses to cancel my contract even though I requested the cancellation within 24 hours. I was told I had a 14 day period in which I could cancel. All telephone calls and emails have been ignored. Initially I wanted to add a phone to my contract, but was told that I had to cancel first. I have been trying, unsuccessfully to cancel from day one. I no longer wish to have any Vodacom contract. I have emailed copies of my correspondence to the addresses provided but Vodacom ignores these.