Passing on personal information to a third party

I keep getting called from this ***. When I answer they hang up and when I call back, as I want to be removed from their list, the call doesn't connect.<br> <br> Why is Vodacom using a Call Centre that does not abide by regulations such as the CPA or the DMASA? I have not provided permission for my details to be provided to a third party so how is this allowed?<br> <br> I want to be removed from Mondo Mobile's contact list immediately.