I tried to upgrade my old 16k sim card to a 64k a couple of months ago. But every vodacom shop i went to in canal walk refused and said i could only upgrade to a 32k sim. They said they only give 64k sims to people with data cards.
Well, I dont know about that, but like I said I have 2. One for my data card and the other for my mobile phone. When I got it last year I was very suprised cause I wasn't aware that Voda had such sim cards. But then again, they are all under my company (corporate contracts).