Vodacom Harassment!!!

I'm being harassed by Vodacom on-billers who call me every single day from this number ***). They dont identify themselves and proceed to offer me silly data packages that overpriced. When I invoke my POPI Act rights they drop the call suddenly only to call me back the next day. Why do I get unsolicited calls? Who is selling our contact data base to on-billers?

This is absolute HARASSMNET AND THE BIGGEST IRONY IS THAT...I'M EMPLOYED BY VODACOM!!!!