Did you complain to WASPA about it? That message would come through a 3rd party, I highly doubt that Vodacom would sanction that kind of information sharing, and if anything there's a leak in the system; getting in an early complaint would help them identify that it and they'd be MORE than happy to crap on them from on high.
By law, a spammer has to divulge where they got the number from, they can't just say "go away".
See, the way it happens is thus:
There's a guy on a keyboard in front of a PC that captures your details while you wait. He then issues your new number and accompanying sim card after all that. Unless we're back before 1994, that PC is on a live network.
That's it man, maybe you can explain how a 3rd party gets that info between the time I hand over my detailed documents to the VC rep, and the time it takes for me to get home and insert the sim into a cell / 3G dongle.
To be honest, I'm stumped.
To answer the 1st part:
Through my many years of taking a very passionate and keen interest in the SA telecomms industry, I've experienced 1st-hand just how much complaining helps. As for the law on disclosure; you deal with a headset jockey who is clueless of that law, tells you that your details were bought as part of a database, but no idea from whom.
No, the manager is busy at the moment. You can phone back later.
Now apply the definition of insanity to the above, or
GIVE your number freely to them so the manager can call you back. We all know how much of a chance there is of that.